11.02.2025, time: 14:00h, place: Kleiner Hörsaal, Linnéstraße 5, in-person talk
In the past decade, there has been an explosion in biology where it is increasingly recognized that there are biological proteins that phase separate out of solution to form protein-dense droplets, termed ‘condensates’. These are found in numerous important biological processes. Increasingly, we find that the exact material nature of the liquid-like condensates (such as their visco-elasticity) is important for proper function in vivo. Interestingly, protein condensates exhibit a range of material properties and behaviors not exhibited by synthetic materials. These include growth into ordered fibers, ultra-low surface tensions, and aging similar to glasses. This diversity of properties and their exact manifestation are ultimately dictated by the amino acid sequence of the proteins that comprise them. Although approaches developed to describe synthetic materials work well to “first approximation”, they cannot describe the intricacies and diversity of material behaviors we observe. Developing such an understanding is a very exciting direction for soft condensed matter physics but is also important for our understanding of how biological systems can harness similar principles to achieve specificity. In this talk, I will present two recent experimental studies in which we uncover how condensate material properties evolve over time. In the first, we discovered that many condensates undergo a transition from liquid-like behavior to more solid-like behavior. This transition has some similarities to aging in glasses while also possessing some unique features. In the second study, I discuss our observations of how condensates associated with neurodegeneration transition to form ordered amyloid-fibers over time. Our experimental observations demonstrate that contrary to the currently expected paradigm, condensates may hinder, not promote fibril formation.
For inquiries please contact Pin-Chuan Chen via email: chen@itp.uni-leipzig.de
If you would like subscribe to the mailing list, please also send a mail to: chen@itp.uni-leipzig.de
TKM-Seminar
TKM-Seminar
TKM-Seminar
BuildMoNa Admission
Mini-Symposium
Master's thesis defense
TKM-Seminar
TKM-Seminar
PhD defense
Master's thesis defense
Master's thesis defense
TKM-Seminar
PhD defense
TKM-Seminar
TKM-Seminar
TKM-Seminar
TKM-Seminar
TKM-Seminar
TKM-SeminarMultiscale heterogeneity, weak limits, and the REV-problem
for porous and heterogeneous media
Rudolf Hilfer (TU Stuttgart)
Past talks (SS 2010)
15.09.2010, time: 09:15h, place: großer SeminarraumQuestions to symmetry breaking in cells and tissues
Prof. Dr. Claus Fütterer
Fiber growth and glass-like aging: Two mechanisms through which protein condensates age
Dr. Louise Jawerth (Huygens – Kamerlingh Onnes Laboratory, Leiden University)In the past decade, there has been an explosion in biology where it is increasingly recognized that there are biological proteins that phase separate out of solution to form protein-dense droplets, termed ‘condensates’. These are found in numerous important biological processes. Increasingly, we find that the exact material nature of the liquid-like condensates (such as their visco-elasticity) is important for proper function in vivo. Interestingly, protein condensates exhibit a range of material properties and behaviors not exhibited by synthetic materials. These include growth into ordered fibers, ultra-low surface tensions, and aging similar to glasses. This diversity of properties and their exact manifestation are ultimately dictated by the amino acid sequence of the proteins that comprise them. Although approaches developed to describe synthetic materials work well to “first approximation”, they cannot describe the intricacies and diversity of material behaviors we observe. Developing such an understanding is a very exciting direction for soft condensed matter physics but is also important for our understanding of how biological systems can harness similar principles to achieve specificity. In this talk, I will present two recent experimental studies in which we uncover how condensate material properties evolve over time. In the first, we discovered that many condensates undergo a transition from liquid-like behavior to more solid-like behavior. This transition has some similarities to aging in glasses while also possessing some unique features. In the second study, I discuss our observations of how condensates associated with neurodegeneration transition to form ordered amyloid-fibers over time. Our experimental observations demonstrate that contrary to the currently expected paradigm, condensates may hinder, not promote fibril formation.
For inquiries please contact Pin-Chuan Chen via email: chen@itp.uni-leipzig.de
If you would like subscribe to the mailing list, please also send a mail to: chen@itp.uni-leipzig.de
06.02.2025, time: 11:00h, place: R211 @ ITP, in-person talk
On the Criticality of the Off-Lattice XY Model Using First-Order Dynamics
Manthan Chattopadhyay (Leipzig Univeristy)
05.12.2024, time: 11:00h, place: R211 @ ITP, in-person talk
Robust Signal Processing in Cellular Networks
Ralf Steuer (Leipzig Univeristy)
21.11.2024, time: 11:00h, place: R211 @ ITP, in-person talk
Influence of Locomotion on Population Dynamics
Paul John (Leipzig Univeristy)
19.07.2024, time: 10:30h, online talk
Non-Reciprocal Interactions Reshape Topological Defect Annihilation
Ylann Rouzaire (Universitat de Barcelona)
16.07.2024, time: 15:30h, in-person talk
Second order response for Langevin Equations with coarse graining
Dan Ionuț (Leipzig University)
11.03.2024, time: 11:00h, online talk
Master Thesis Progress
Nils Antary
29.02.2024, time: 14:00h, Master Defense (In-Person)
Glassy behaviour, phases, and vortices of a non-reciprocal spin system
Thomas Ullmann
24.01.2024, time: 9:00h, Online talk
Numerical analysis of macroscopic states and computational capacity of sparsely connected QIF neuron populations and investigation of a corresponding mean-field model
Wilhelm Witzleb
15.01.2024, time: 11:00h, Online talk
Tracing noisy gradients: chemotactic motion in fluctuating environments
Thomas Suchanek (ITP Leipzig)
01.12.2023, time: 9:30h, PhD Defense (hybrid)
Optimization of thermodynamics systems
Zhuolin Ye (Leipzig University)
13.10.2023, time: 11:00h, Online talk
Interpolation and sampling effects on recurrence quantification measures
Nils Antary (Leipzig University)
02.08.2023, time: 11:00h, Mid-term exam
Force-Free and Autonomous Active Brownian Ratchets
Constantin Rein (Leipzig University)
12.07.2023, time: 15:00h, Online Talk
Activated dynamics of glass-forming liquids
Ankit Singh (Banaras Hindu University)
11.07.2023, time: 15:00h, Online Talk
Universal phenomenology at critical exceptional points of nonequilibrium O(N) models
Carl Philipp Zelle (Universität zu Köln)
04.07.2023, time: 15:00h, Online Talk
Cavitation instablities in amorphous solids
Umang Dattani (IMS Chennai)
04.07.2023, time: 11:00h, Online Talk
Fluctuation-induced interactions in atomic physics
Dr. Daniel Reiche (Humboldt Univeristy)
04.04.2023, time: 10:00h, In-person Talk
The Scaling Behavior of Windblown Sand and Fluvial Bedload Transport
Prof. Dr. Thomas Pähtz (Zhejian University)
24.03.2023, time: 11:00h, Online Talk
Mediations on the Vicsek Model
Robert Horton (University of Leipzig)
15.03.2023, time: 11:00h, Online Talk
Nonequilibrium dynamics and steady-states
Chandraniva Guha Ray (IISER)
17.02.2023, time: 11:00h, PhD Defense
Effects of Time Delay in Motile Active Matter – From microscopic to collective behavior
Daniel Geiß (ITP Leipzig)
21.12.2022, time: 11:00h, Online Talk
Kinetic Field Theory applied to Cosmic Structure Formation
Şafak Çelik (Heidelberg University)
25.10.2022, time: 10:00h, Online Talk
Spontaneous vortex formation by microswimmers with retarded attractions
Pin-Chuan Chen (ITP Leipzig)
15.07.2022, time: 11:00h, Online Talk
Mean field modeling of recurrent neural networks
Wilhelm Witzleb
30.06.2022, time: 15:00h, Talk
Planetary rings: Mechanics and mysteries
Shribharath (IIT Kanpur)
15.06.2022, time: 17:15h, Talk
Response Theory: A Trajectory-Based Approach
Lokrshi Dadhichi (Univeristy of Leipzig)
10.06.2022, time: 11:00h, Online Talk
Recurrent-Neural-Network Computation und Reservoir Computing
Wilhelm Witzleb
08.06.2022, time: 17:00h, Online Talk
Thermodynamic Uncertainty Relation for Charged Transport: Multilevel Setup
Bhavesh Valecha (IISER Pune)
22.04.2022, time: 11:00h, Online Talk
Master Thesis Defense: Steady state entropy production in dynamical field theories with non-reciprocal coupling
Thomas Suchanek (Univerity of Leipzig)
24.03.2022, time: 20:00h, Online Talk
Josiah Cleland (Massey University)
08.03.2022, time: 14:00h, Online Talk
Irreversible dynamics and entropy production in stochastic field theories with non reciprocal coupling
Thomas Suchanek (Univerity of Leipzig)
17.02.2022, time: 14:00h, Online Talk
Semigroup Approach to Second Order Response in Coarse Grained Systems
Fenna Müller (Univerity of Leipzig)
21.01.2022, time: 11:00h, Online Talk
Power-law Stochastic Resetting in the Symmetric Exclusion Process
Seemant Mishra (IISER Pune)
20.12.2021, time: 14:00h, Online Talk
Intermittency in the passive slider problem and Fixation in population dynamics
Tapas Singha (University of Massachusetts Amherst)
25.10.2021, time: 11:00h, Online Talk
Odd Elasticity
Lokrshi Parwar Dadhichi (University of Leipzig)
27.09.2021, time: 11:00h, Online Talk
Total segment distribution about the center of mass of a single Gaussian polymer chain in an external harmonic potential
Tobias Thalheim (University of Leipzig)
20.09.2021, time: 11:00h, Online Talk
Mesoscale phenomena in sand transport and pattern formation
Katharina Tholen (University of Leipzig)
19.07.2021, time: 11:00h, Online Talk
Force-free Brownian ratchet
Constantin Rein (University of Leipzig)
05.07.2021, time: 11:00h, Online Talk
Multi-scale heterogeneity in viral disease spread
Sander Claes (University of Leipzig)
21.06.2021, time: 11:00h, Online Talk
Superdiffusion and hydrodynamic condensation in uniaxial active suspensions
Lokrshi Parwar Dadhichi (University of Leipzig)
14.06.2021, time: 11:00h, Online Talk
Bi-stable rotation modes formed by active particles with retarded interactions
Pin-Chuan Chen (University of Leipzig)
07.06.2021, time: 11:00h, Online Talk
Unified model of sediment transport threshold and rate across subaqueous bedload, windblown sand, and windblown snow
Thomas Pähtz (Zhejiang University)
21.05.2021, time: 15:15h, Online Talk
Physics of Collective Behavior: Perturbed Insect Swarms
Michael Sinhuber (Univerity of Oldenburg)
13.04.2021, time: 14:00h, Online Talk
Response Theory for Stochastic Processes: Entropy Production and Coarse-graining
Fenna Müller (Leipzig University)
18.03.2021, time: 16:00h, Online Talk
Aspects of Skewed Range Expansion
Oskar Hallatschek (University of California, Berkeley)
03.02.2021, time: 16:15h, Online Talk
TKM-Seminar
Cultural evolution: mathematical models of culture change
Laurel Fogarty (MPG EVA, Leipzig)
18.01.2021, time: 15:15h, Online Talk
TKM-Seminar
Molecular friction in liquids: bridging between the atomistic and hydrodynamic pictures
Prof. Dr. Felix Höfling (FU Berlin)
13.01.2021, time: 16:15h, Online Talk
TKM-Seminar
Non-mutual interactions, not motility, as the heart of active matter
Lokrshi Dadhichi (TIFR Hyderabad)
28.09.2020, time: 14:00h, SR 210, ITP
Fairy Circles
Dr. Stephan Getzin (University of Göttingen)
14.07.2020, time: 14:00h, SR 210, ITP
BuildMoNa Admission
The optimization of thermodynamic devices
Zhuolin Ye, M.Sc.
26.06.2020, time: 13:00h, via web conference
Mini-Symposium
Polarization of Brownian swimmers with spatially heterogeneous activity
Sven Auscha, M.Sc.The polarization field of microswimmers at motility steps
Nicola Söker, M.Sc.Power functional theory and active polarization
Prof. Dr Matthias Schmidt (University of Bayreuth)
16.03.2020, time: 12:15h, place: SR 114, ITP
Regularization of dipoles in second gradient electrodynamics
Jakob Leck, M.Sc.
19.12.2019, time: 12:00h, place: SR 114, ITP
Master's thesis defense
t.b.a.
Cand. M. Sc. Roland Wiese
18.12.2019, time: 15:00h, place: SR 114, ITP
TKM-Seminar
Phase transitions and tracer kinetics in far-from-equilibrium Brownian dynamics
Demian Levis (University of Barcelona)
26.09.2019, time: 16:00h, place: SR 113, ITP
TKM-Seminar
From sand pile to migrating dune - morphological transition of a barchan in a laboratory wind tunnel
Merve Seckin-Kryger (DLR), M. Sc.
26.09.2019, time: 11:00h, place: SR 113, ITP
Brownian Molecules Formed by Delayed Harmonic Interactions
Dr. Viktor Holubec
12.09.2019, time: 14:30h, place: SR 114, ITP
PhD defense
Mesoscopic concepts in soft condensed matter physics. From wind-blown sand to biopolymer solutions
Marc Lämmel, Cand. PhD
30.08.2019, time: 18:00h, place: SR 114, ITP
Master's thesis defense
About self-thermophoretic Janus microswimmers in spatially heterogeneous activity profiles
Cand. M. Sc. Paul Cervenak
20.08.2019, time: 11:00h, place: SR 114, ITP
Brownian Particles interacting via long-ranged delayed potentials
Matthew Hagley
14.08.2019, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Nonisothermal monomer dynamics of a wormlike chain
Cand. M. Sc. Joscha Mecke
27.06.2019, time: 14:00h, place: SR 113, ITP
Nonisothermal monomer dynamics of a wormlike chain
Joscha Mecke, B. Sc.
17.06.2019, time: 13:00h, place: SR 114, ITP
TKM-Seminar
Phase transitions and tracer kinetics in far-from-equilibrium Brownian dynamics
Dr. Artem Ryabov (Charles University, Prague)
21.05.2019, time: 10:00h, place: SR 114, ITP
PhD defense
Active systems: from heat engines to active baths
Stefano Steffenoni, Cand. PhD
14.05.2019, time: 13:00h, place: SR 114, ITP
TKM-Seminar
Time-delayed stochastic processes – Fokker-Planck approach, Markovian embedding and thermodynamic notions
Sarah Loos, M. Sc. (TU Berlin)
07.05.2019, time: 13:00h, place: SR 114, ITP
TKM-Seminar
Critical Dynamics in Neural Network
Masud Ehsani, M. Sc. (MPI MiS, Leipzig)
04.04.2019, time: 11:30h, place: SR 114, ITP
TKM-Seminar
A granular bed sheared by flow of a Newtonian fluid
Dr. Thomas Pähtz (Ocean College, Zhejiang University)
27.03.2019, time: 11:00h, place: SR 114, ITP
Why is the desert not flat? and Conditions of megaripple formation
Prof. Dr. Klaus Kroy and Katharina Tholen, M. Sc.
20.03.2019, time: 11:00h, place: SR 114, ITP
TKM-Seminar
The fractality of breath figures
Daniel Dernbach, B. Sc.
06.03.2019, time: 11:30h, place: SR 114, ITP
TKM-Seminar
Ripening, focusing and splitting of aggregate size distributions
Prof. Dr. Jürgen Vollmer (University of Leipzig)
19.02.2019, time: 15:00h, place: SR 211, ITP
Polarization of Brownian swimmers with spatially heterogeneous activity
Sven Auschra, M. Sc.
14.02.2019, time: 11:00h, place: SR 114, ITP
The inhomogeneous chain ensemble for semiflexible polymer networks
Constantin Huster, M. Sc.
29.01.2019, time: 15:15h, place: SR 211, ITP
The geometry of dynamical models of evolution
Camila Bräutigam, B. Sc.
28.01.2019, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Multiscale heterogeneity, weak limits, and the REV-problem
for porous and heterogeneous media
Rudolf Hilfer (TU Stuttgart)
15.01.2019, time: 15:00h, place: SR 211, ITP
Semiflexible polymers in non-isothermal environment
Joscha Mecke, B. Sc.
26.09.2018, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Discrete-Element Simulation Framework For Adherent Cells
Cand. M. Sc. Benjamin Streitz
23.08.2018, time: 16:00h, place: SR 210, ITP
TKM-Seminar
Criticality and energy-landscape dynamics in the reversibility-irreversibility transition in amorphous solids under oscillatory shear
Ido Regev (Ben-Gurion University of the Negev)
Recently it was shown that under oscillatory shear at zero temperature, the response of an amorphous solid under oscillatory shear transitions from periodic to diffusive at a critical strain amplitude. However, the physical reason for this transition is still not understood. We show, using computer simulations, that the mean-square displacement of the particles in the amorphous solid exhibit scaling typical of second order phase transition and that the diffusive behavior is reminiscent of the dynamics of particles diffusing in a percolating network. We explain this similarity by studying models of diffusion on an energy landscape and show that these models can describe qualitatively some of the behavior observed in amorphous solids.
23.08.2018, time: 11:00h, place: SR 114, ITP
Master's thesis defense
A Survey on nonlinear Microrheology
Cand. M. Sc. Katharina Tholen
05.07.2018, time: 11:30h, place: SR 113, ITP
Kinetic theory of self-propelled particles
Prof. Dr. Thomas Ihle (University of Greifswald)
09.05.2018, time: 11:30h, place: SR 211, ITP
Effects of polymeric linkers in Single Molecule Force Spectroscopy
Ephraim Bernhardt
06.03.2018, time: 11:00h, place: SR 210, ITP
TKM-Seminar
Effective forces and interactions induced by nonequilibrium media
Karel Netocny, PhD (Institute of Physics AS CR))
In my talk I will discuss properties of the effective forces induced by a nonequilibrium medium on attached quasistatic probe(s). In contrast to equilibrium, these forces neither derive from a thermodynamic potential, nor they generally allow for a simple thermodynamic interpretation, and the kinetic aspects of the dynamics become relevant. In the case of multiple probes we observe the emergence of effective interactions which exhibit long-range features and break the action-reaction principle. It will be demonstrated via simple models how the nonequilibrium driving can induce stability of (i) a single-probe configuration, (ii) a multiple-probe pattern which are both unstable under equilibrium conditions.
[1] U. Basu, C. Maes, and K. N., Phys. Rev. Lett. 114, 250601 (2015)
[2] U. Basu, P. de Buyl, C. Maes, and K. N., Europhys. Lett. 115, 30007 (2016)
[3] C. Maes and K. N., arXiv:1711.05168
21.02.2018, time: 11:15h, place: SR 114, ITP
Talk Theoretikum
Properties of active Brownian particles in presence of inhomogenous activity
Paul Cervenak, B.Sc.
30.01.2018, time: 14:30h, place: SR 211, ITP
Zwischenprüfung
Effective nonequilibrium temperatures and polarization of hot microswimmers
Sven Auschra, M.Sc.
10.01.2018, time: 11:15h, place: SR 113, ITP
Effects of noise-induced coherence on the performance of quantum absorption refrigerators
Dr. Victor Holubec
We study two models of quantum absorption refrigerators with the main focus on discerning the role of noise-induced coherence on their thermodynamic performance. Analogously to the previous studies on quantum heat engine we find the increase in the cooling power due to the mechanism of noise-induce coherence. We formulate conditions imposed on the microscopic parameters of the models under which they can be equivalently described by classical stochastic processes and compare the performance of the two classes of fridges (effectively classical vs. truly quantum). We find out that the enhanced performance is observed already for the effectively classical systems with no qualitative change in the quantum cases, which suggests that the noise-induced-coherence enhancement mechanism is caused by static
interference phenomena.
09.11.2017, time: 11:00h, place: SR 211, ITP
Zwischenprüfung
Nonequilibrium baths: broken symmetries and other flavours
Stefano Steffenoni, M.Sc.
11.10.2017, time: 14:00h, place: SR 114, ITP
TKM-Seminar
Active microrheology in complex fluids
Markus Gruber, M.Sc. (University of Konstanz)
11.07.2017, time: 15:00h, place: SR 113, ITP
Zwischenprüfung
Microstructure of sheared entangled solutions of semiflexible polymers
Dipl. Phys. Marc Lämmel
05.07.2017, time: 12:00h, place: SR 113, ITP
TKM-Seminar
Statistical laws of Darwinian evolution
Matteo Smerlak (Perimeter Institute for Theoretical Physics, Waterloo (Ontario) in Canada)
28.06.2017, time: 14:00h, place: SR 210, ITP
PhD defense
A unified theory for single-molecule force spectroscopy experiments and simulations
Cand. Dr. Jakob T. Bullerjahn
22.06.2017, time: 11:15h, place: SR 113, ITP
A unified theory for single-molecule force spectroscopy experiments and simulations
Dipl. Phys. Jakob T. Bullerjahn
30.05.2017, time: 15:00h, place: SR 113, ITP
Stirling cycle and active baths: can active matter enhance the efficiency?
Stefano Steffenoni, M.Sc.
29.05.2017, time: 10:00h, place: SR 114, ITP
PhD defense
Four out-of-equilibrium stories
Cand. Dr. Gianmaria Falasco
19.04.2017, time: 14:00h, place: SR 113, ITP
TKM-Seminar
Molecular mechanics of biological and biomimetic materials
Dr. K. Blank (MPI of Colloids and Interfaces)
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
Recently it was shown that under oscillatory shear at zero temperature, the response of an amorphous solid under oscillatory shear transitions from periodic to diffusive at a critical strain amplitude. However, the physical reason for this transition is still not understood. We show, using computer simulations, that the mean-square displacement of the particles in the amorphous solid exhibit scaling typical of second order phase transition and that the diffusive behavior is reminiscent of the dynamics of particles diffusing in a percolating network. We explain this similarity by studying models of diffusion on an energy landscape and show that these models can describe qualitatively some of the behavior observed in amorphous solids.
23.08.2018, time: 11:00h, place: SR 114, ITP
Master's thesis defense
A Survey on nonlinear Microrheology
Cand. M. Sc. Katharina Tholen
05.07.2018, time: 11:30h, place: SR 113, ITP
Kinetic theory of self-propelled particles
Prof. Dr. Thomas Ihle (University of Greifswald)
09.05.2018, time: 11:30h, place: SR 211, ITP
Effects of polymeric linkers in Single Molecule Force Spectroscopy
Ephraim Bernhardt
06.03.2018, time: 11:00h, place: SR 210, ITP
TKM-Seminar
Effective forces and interactions induced by nonequilibrium media
Karel Netocny, PhD (Institute of Physics AS CR))
In my talk I will discuss properties of the effective forces induced by a nonequilibrium medium on attached quasistatic probe(s). In contrast to equilibrium, these forces neither derive from a thermodynamic potential, nor they generally allow for a simple thermodynamic interpretation, and the kinetic aspects of the dynamics become relevant. In the case of multiple probes we observe the emergence of effective interactions which exhibit long-range features and break the action-reaction principle. It will be demonstrated via simple models how the nonequilibrium driving can induce stability of (i) a single-probe configuration, (ii) a multiple-probe pattern which are both unstable under equilibrium conditions.
[1] U. Basu, C. Maes, and K. N., Phys. Rev. Lett. 114, 250601 (2015)
[2] U. Basu, P. de Buyl, C. Maes, and K. N., Europhys. Lett. 115, 30007 (2016)
[3] C. Maes and K. N., arXiv:1711.05168
21.02.2018, time: 11:15h, place: SR 114, ITP
Talk Theoretikum
Properties of active Brownian particles in presence of inhomogenous activity
Paul Cervenak, B.Sc.
30.01.2018, time: 14:30h, place: SR 211, ITP
Zwischenprüfung
Effective nonequilibrium temperatures and polarization of hot microswimmers
Sven Auschra, M.Sc.
10.01.2018, time: 11:15h, place: SR 113, ITP
Effects of noise-induced coherence on the performance of quantum absorption refrigerators
Dr. Victor Holubec
We study two models of quantum absorption refrigerators with the main focus on discerning the role of noise-induced coherence on their thermodynamic performance. Analogously to the previous studies on quantum heat engine we find the increase in the cooling power due to the mechanism of noise-induce coherence. We formulate conditions imposed on the microscopic parameters of the models under which they can be equivalently described by classical stochastic processes and compare the performance of the two classes of fridges (effectively classical vs. truly quantum). We find out that the enhanced performance is observed already for the effectively classical systems with no qualitative change in the quantum cases, which suggests that the noise-induced-coherence enhancement mechanism is caused by static
interference phenomena.
09.11.2017, time: 11:00h, place: SR 211, ITP
Zwischenprüfung
Nonequilibrium baths: broken symmetries and other flavours
Stefano Steffenoni, M.Sc.
11.10.2017, time: 14:00h, place: SR 114, ITP
TKM-Seminar
Active microrheology in complex fluids
Markus Gruber, M.Sc. (University of Konstanz)
11.07.2017, time: 15:00h, place: SR 113, ITP
Zwischenprüfung
Microstructure of sheared entangled solutions of semiflexible polymers
Dipl. Phys. Marc Lämmel
05.07.2017, time: 12:00h, place: SR 113, ITP
TKM-Seminar
Statistical laws of Darwinian evolution
Matteo Smerlak (Perimeter Institute for Theoretical Physics, Waterloo (Ontario) in Canada)
28.06.2017, time: 14:00h, place: SR 210, ITP
PhD defense
A unified theory for single-molecule force spectroscopy experiments and simulations
Cand. Dr. Jakob T. Bullerjahn
22.06.2017, time: 11:15h, place: SR 113, ITP
A unified theory for single-molecule force spectroscopy experiments and simulations
Dipl. Phys. Jakob T. Bullerjahn
30.05.2017, time: 15:00h, place: SR 113, ITP
Stirling cycle and active baths: can active matter enhance the efficiency?
Stefano Steffenoni, M.Sc.
29.05.2017, time: 10:00h, place: SR 114, ITP
PhD defense
Four out-of-equilibrium stories
Cand. Dr. Gianmaria Falasco
19.04.2017, time: 14:00h, place: SR 113, ITP
TKM-Seminar
Molecular mechanics of biological and biomimetic materials
Dr. K. Blank (MPI of Colloids and Interfaces)
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
06.03.2018, time: 11:00h, place: SR 210, ITP
TKM-Seminar
Effective forces and interactions induced by nonequilibrium media
Karel Netocny, PhD (Institute of Physics AS CR))
In my talk I will discuss properties of the effective forces induced by a nonequilibrium medium on attached quasistatic probe(s). In contrast to equilibrium, these forces neither derive from a thermodynamic potential, nor they generally allow for a simple thermodynamic interpretation, and the kinetic aspects of the dynamics become relevant. In the case of multiple probes we observe the emergence of effective interactions which exhibit long-range features and break the action-reaction principle. It will be demonstrated via simple models how the nonequilibrium driving can induce stability of (i) a single-probe configuration, (ii) a multiple-probe pattern which are both unstable under equilibrium conditions.
[1] U. Basu, C. Maes, and K. N., Phys. Rev. Lett. 114, 250601 (2015)
[2] U. Basu, P. de Buyl, C. Maes, and K. N., Europhys. Lett. 115, 30007 (2016)
[3] C. Maes and K. N., arXiv:1711.05168
21.02.2018, time: 11:15h, place: SR 114, ITP
Talk Theoretikum
Properties of active Brownian particles in presence of inhomogenous activity
Paul Cervenak, B.Sc.
30.01.2018, time: 14:30h, place: SR 211, ITP
Zwischenprüfung
Effective nonequilibrium temperatures and polarization of hot microswimmers
Sven Auschra, M.Sc.
10.01.2018, time: 11:15h, place: SR 113, ITP
Effects of noise-induced coherence on the performance of quantum absorption refrigerators
Dr. Victor Holubec
We study two models of quantum absorption refrigerators with the main focus on discerning the role of noise-induced coherence on their thermodynamic performance. Analogously to the previous studies on quantum heat engine we find the increase in the cooling power due to the mechanism of noise-induce coherence. We formulate conditions imposed on the microscopic parameters of the models under which they can be equivalently described by classical stochastic processes and compare the performance of the two classes of fridges (effectively classical vs. truly quantum). We find out that the enhanced performance is observed already for the effectively classical systems with no qualitative change in the quantum cases, which suggests that the noise-induced-coherence enhancement mechanism is caused by static
interference phenomena.
09.11.2017, time: 11:00h, place: SR 211, ITP
Zwischenprüfung
Nonequilibrium baths: broken symmetries and other flavours
Stefano Steffenoni, M.Sc.
11.10.2017, time: 14:00h, place: SR 114, ITP
TKM-Seminar
Active microrheology in complex fluids
Markus Gruber, M.Sc. (University of Konstanz)
11.07.2017, time: 15:00h, place: SR 113, ITP
Zwischenprüfung
Microstructure of sheared entangled solutions of semiflexible polymers
Dipl. Phys. Marc Lämmel
05.07.2017, time: 12:00h, place: SR 113, ITP
TKM-Seminar
Statistical laws of Darwinian evolution
Matteo Smerlak (Perimeter Institute for Theoretical Physics, Waterloo (Ontario) in Canada)
28.06.2017, time: 14:00h, place: SR 210, ITP
PhD defense
A unified theory for single-molecule force spectroscopy experiments and simulations
Cand. Dr. Jakob T. Bullerjahn
22.06.2017, time: 11:15h, place: SR 113, ITP
A unified theory for single-molecule force spectroscopy experiments and simulations
Dipl. Phys. Jakob T. Bullerjahn
30.05.2017, time: 15:00h, place: SR 113, ITP
Stirling cycle and active baths: can active matter enhance the efficiency?
Stefano Steffenoni, M.Sc.
29.05.2017, time: 10:00h, place: SR 114, ITP
PhD defense
Four out-of-equilibrium stories
Cand. Dr. Gianmaria Falasco
19.04.2017, time: 14:00h, place: SR 113, ITP
TKM-Seminar
Molecular mechanics of biological and biomimetic materials
Dr. K. Blank (MPI of Colloids and Interfaces)
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
30.01.2018, time: 14:30h, place: SR 211, ITP
Zwischenprüfung
Effective nonequilibrium temperatures and polarization of hot microswimmers
Sven Auschra, M.Sc.
10.01.2018, time: 11:15h, place: SR 113, ITP
Effects of noise-induced coherence on the performance of quantum absorption refrigerators
Dr. Victor Holubec
We study two models of quantum absorption refrigerators with the main focus on discerning the role of noise-induced coherence on their thermodynamic performance. Analogously to the previous studies on quantum heat engine we find the increase in the cooling power due to the mechanism of noise-induce coherence. We formulate conditions imposed on the microscopic parameters of the models under which they can be equivalently described by classical stochastic processes and compare the performance of the two classes of fridges (effectively classical vs. truly quantum). We find out that the enhanced performance is observed already for the effectively classical systems with no qualitative change in the quantum cases, which suggests that the noise-induced-coherence enhancement mechanism is caused by static
interference phenomena.
09.11.2017, time: 11:00h, place: SR 211, ITP
Zwischenprüfung
Nonequilibrium baths: broken symmetries and other flavours
Stefano Steffenoni, M.Sc.
11.10.2017, time: 14:00h, place: SR 114, ITP
TKM-Seminar
Active microrheology in complex fluids
Markus Gruber, M.Sc. (University of Konstanz)
11.07.2017, time: 15:00h, place: SR 113, ITP
Zwischenprüfung
Microstructure of sheared entangled solutions of semiflexible polymers
Dipl. Phys. Marc Lämmel
05.07.2017, time: 12:00h, place: SR 113, ITP
TKM-Seminar
Statistical laws of Darwinian evolution
Matteo Smerlak (Perimeter Institute for Theoretical Physics, Waterloo (Ontario) in Canada)
28.06.2017, time: 14:00h, place: SR 210, ITP
PhD defense
A unified theory for single-molecule force spectroscopy experiments and simulations
Cand. Dr. Jakob T. Bullerjahn
22.06.2017, time: 11:15h, place: SR 113, ITP
A unified theory for single-molecule force spectroscopy experiments and simulations
Dipl. Phys. Jakob T. Bullerjahn
30.05.2017, time: 15:00h, place: SR 113, ITP
Stirling cycle and active baths: can active matter enhance the efficiency?
Stefano Steffenoni, M.Sc.
29.05.2017, time: 10:00h, place: SR 114, ITP
PhD defense
Four out-of-equilibrium stories
Cand. Dr. Gianmaria Falasco
19.04.2017, time: 14:00h, place: SR 113, ITP
TKM-Seminar
Molecular mechanics of biological and biomimetic materials
Dr. K. Blank (MPI of Colloids and Interfaces)
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
We study two models of quantum absorption refrigerators with the main focus on discerning the role of noise-induced coherence on their thermodynamic performance. Analogously to the previous studies on quantum heat engine we find the increase in the cooling power due to the mechanism of noise-induce coherence. We formulate conditions imposed on the microscopic parameters of the models under which they can be equivalently described by classical stochastic processes and compare the performance of the two classes of fridges (effectively classical vs. truly quantum). We find out that the enhanced performance is observed already for the effectively classical systems with no qualitative change in the quantum cases, which suggests that the noise-induced-coherence enhancement mechanism is caused by static interference phenomena.
09.11.2017, time: 11:00h, place: SR 211, ITP
Zwischenprüfung
Nonequilibrium baths: broken symmetries and other flavours
Stefano Steffenoni, M.Sc.
11.10.2017, time: 14:00h, place: SR 114, ITP
TKM-Seminar
Active microrheology in complex fluids
Markus Gruber, M.Sc. (University of Konstanz)
11.07.2017, time: 15:00h, place: SR 113, ITP
Zwischenprüfung
Microstructure of sheared entangled solutions of semiflexible polymers
Dipl. Phys. Marc Lämmel
05.07.2017, time: 12:00h, place: SR 113, ITP
TKM-Seminar
Statistical laws of Darwinian evolution
Matteo Smerlak (Perimeter Institute for Theoretical Physics, Waterloo (Ontario) in Canada)
28.06.2017, time: 14:00h, place: SR 210, ITP
PhD defense
A unified theory for single-molecule force spectroscopy experiments and simulations
Cand. Dr. Jakob T. Bullerjahn
22.06.2017, time: 11:15h, place: SR 113, ITP
A unified theory for single-molecule force spectroscopy experiments and simulations
Dipl. Phys. Jakob T. Bullerjahn
30.05.2017, time: 15:00h, place: SR 113, ITP
Stirling cycle and active baths: can active matter enhance the efficiency?
Stefano Steffenoni, M.Sc.
29.05.2017, time: 10:00h, place: SR 114, ITP
PhD defense
Four out-of-equilibrium stories
Cand. Dr. Gianmaria Falasco
19.04.2017, time: 14:00h, place: SR 113, ITP
TKM-Seminar
Molecular mechanics of biological and biomimetic materials
Dr. K. Blank (MPI of Colloids and Interfaces)
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
22.06.2017, time: 11:15h, place: SR 113, ITP
A unified theory for single-molecule force spectroscopy experiments and simulations
Dipl. Phys. Jakob T. Bullerjahn
30.05.2017, time: 15:00h, place: SR 113, ITP
Stirling cycle and active baths: can active matter enhance the efficiency?
Stefano Steffenoni, M.Sc.
29.05.2017, time: 10:00h, place: SR 114, ITP
PhD defense
Four out-of-equilibrium stories
Cand. Dr. Gianmaria Falasco
19.04.2017, time: 14:00h, place: SR 113, ITP
TKM-Seminar
Molecular mechanics of biological and biomimetic materials
Dr. K. Blank (MPI of Colloids and Interfaces)
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
29.05.2017, time: 10:00h, place: SR 114, ITP
PhD defense
Four out-of-equilibrium stories
Cand. Dr. Gianmaria Falasco
19.04.2017, time: 14:00h, place: SR 113, ITP
TKM-Seminar
Molecular mechanics of biological and biomimetic materials
Dr. K. Blank (MPI of Colloids and Interfaces)
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
13.01.2017, time: 11:00h, place: SR 113, ITP
Zwischenprüfung
Linear response out of equilibrium
Gianmaria Falasco, M.Sc.
06.01.2017, time: 14:00h, place: SR 211, ITP
The role of spatial structure in microbial evolution
Matti Gralka, M.Sc. (University of California, Berkeley)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
23.11.2016, time: 11:00h, place: SR 114, ITP
TKM-Seminar
Cell type dependent mechanics of composite cytoskeletal networks
Prof. Dr. K. Gottschalk (Ulm University)
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
08.11.2016, time: 14:15h, place: SR 113, ITP
PhD thesis defense
Kinetics and dynamics of single biomolecules
Cand. Dr. Sebastian Sturm
03.11.2016, time: 16:00h, place: SR 211, ITP
Kinetics and dynamics of single biomolecules
Dipl. Phys. S. Sturm
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
02.11.2016, time: 10:00h, place: SR 114, ITP
TKM-Seminar
Thermodynamics of error correction
Dr. S. Pigolotti (Universitat Politècnica de Catalunya, Barcelona
Biological systems are able to replicate information with outstanding accuracy. In biochemical reactions, such as DNA duplication, different monomers can be distinguished because of their binding energies or via non-equilibrium kinetic mechanisms. I will show how, in simple copying reactions, these two discrimination modes are mutually exclusive and lead to opposite tradeoffs between error, dissipation and reaction velocity. In multi-step reactions, such as in kinetic proofreading, these different modes can be combined to improve overall accuracy. I will conclude by discussing how the second law of thermodynamics can be used to directly relate copying accuracy with thermodynamic observables.
Refs:
P. Sartori and S. Pigolotti, Phys. Rev. Lett. 110, 188101, 2013.
P. Sartori and S. Pigolotti, Phys. Rev. X 5, 041039, 2015
S. Pigolotti and P. Sartori, J. Stat. Phys. 162(5), 1167-1182, 2016.
>28.09.2016, time: 16:30h, place: SR 113, ITP
TKM-Seminar
Physics and modeling of dune formation
Dr. E. Parteli (University of Cologne)
Sand dunes occur in deserts and coastal areas of our planet and also on Mars, Venus and Titan. Dunes have been also detected on the comet 67P/Churyumov-Gerasimenko and may dominate vast areas of Pluto. The quantitative understanding of dune dynamics is thus important not only for the development of efficient measures to combat desertification but also for the investigation of wind systems in extraterrestrial environments. This understanding experienced great advance in the last years with the development of a continuum dune model [Kroy et al. PRE 88, 054301 (2002); Parteli et al. EPJST 223, 2269-2283 (2014)], which describes the morphology and dynamics of dunes of different types with quantitative agreement with field measurements. In this seminar I will talk about the physics of sand transport and dune formation and show how the dune model is becoming a powerful tool for the quantitative research in different areas of Earth and Planetary Sciences.
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
13.09.2016, time: 15:15h, place: SR 113, ITP
Master's thesis defense
Stability of Barchan Dunes
Cand. M.Sc. Mona Guthardt
30.08.2016, time: 17:00h, place: SR 113, ITP
Master's thesis defense
A Framework for Inelastic Biomechanics
Cand. M.Sc. Constantin Huster
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
18.07.2016, time: 15:00h, place: SR 211, ITP
Equilibrium and Non-Equilibrium Glassy Worm-like Chains
Constantin Huster, B.Sc.
18.07.2016, time: 11:30h, place: SR 211, ITP
The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled
Tobias Göppel, B.Sc. (TU Munich)
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a driftâdiffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
06.07.2016, time: 15:15h, place: SR 114, ITP
TKM-Seminar
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
Dr. W. Till Kranz (DLR)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
29.06.2016, time: 15:00h, place: SR 114, ITP
Pressure of active particles
Stefano Steffenoni, M.Sc.
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
15.06.2016, time: 11.00h, place: ITP, SR 113
TKM-Seminar
Self-similar aftershock rates
Prof. Marco Baiesi (University of Padova)
There are several empirical observations, ranging from rock fracture to regional seismic activity, suggesting that crackling noise and earthquakes take place as a scale-free process. However, to date, one of the main laws of seismicity, namely the Omori law for aftershock rate decay, is expressed in a form that is not scale invariant. We show that a modified version of the Omori law fits well the rates extracted from high precision earthquake catalogs. The new law is based on the typical scaling form of critical phenomena and provides some closure in our description of seismicity as a scale-free phenomenon. This has practical implications, as it should be taken into account in the epidemic models used to assess the seismic hazard.
12.05.2016, time: 11:00h, place: SR 113, ITP
Self-consistent Determination of Temporal Correlations in Non-linear Systems: Application to a Bistable System
B.Sc. Daniel Rose
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
20.04.2016, time: 14:00h, place: SR 211, ITP
TKM-Seminar
Driving Rate Dependence of Avalanche Statistics at the Yielding Transition of Amorphous Solids
Ezequiel Ferrero (Université Grenoble Alpes)
24.02.2016, time: 15:00h, place: SR 211, ITP
Self-consistent determination of temporal correlations in non-linear systems
B.Sc. Daniel Rose
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
11.02.2016, time: 15:00h, place: SR 114, ITP
Viscoelasticity of transiently cross-linked biopolymer networks
B.Sc. Andreas Fischer
11.02.2016, time: 11:00h, place: SR 211, ITP
Dunes in inhomogeneous flux fields: When are barchans stable?
B.Sc. Mona Guthardt
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
28.01.2016, time: 11:00h, place: SR 211, ITP
The unbearable Lightness of Pressure. The pressure of active particles
M.Sc. Stefano Steffenoni
21.01.2016, time: 11:00h, place: SR 211, ITP
Non-Markovian escape processes: Markovian limits and beyond
Dipl. Phys. Jakob Bullerjahn
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
14.01.2016, time: 11:00h, place: SR 211, ITP
Mapping channel-confined DNA to a 1D random walk
Erik Werner, PhD, University of Gothenburg
15.12.2015, time: 13:00h, place: SR 211, ITP
Master's thesis defense
Linear and nonlinear microrheology
Cand. M.Sc. Tim Herpich
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
03.12.2015, time: 11:00h, place: SR 211, ITP
Linear and nonlinear microrheology
B.Sc. Tim Herpich
19.11.2015, time: 13:00h, place: SR 211, ITP
Mesoscale modeling of aeolian sand transport
Dipl. Phys. Marc Lämmel
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
05.11.2015, time: 11:00h, place: SR 211, ITP
Understanding sand dunes
M.Sc. Sven Auschra
22.10.2015, time: 11:00h, place: SR 211, ITP
On the fluctuation theorems, old and new
M.Sc. Gianmaria Falasco
The so-called fluctuation theorems (FTs) describe symmetries of the statistics of certain physical observables in systems far from thermodynamic equilibrium. First, I will give an overview of the different formal settings in which they have been derived --dynamical systems, thermostatted Hamiltonian mechanics, stochastic dynamics-- and present briefly their potential utility in tackling fundamental problems (e.g. how irreversibility emerges from reversible dynamics) as well as practical ones (e.g. how to obtain equilibrium properties from non-equilibrium measurements). Then, I will argue that all FTs stem from the breaking of certain dynamical symmetries caused by the non-equilibrium driving. The most prominent example is time-reversal invariance yielding FRs for the entropy production, which are refinements of the second law of thermodynamics. Moreover, spacial transformations are known which give generalized FRs for the probabilities of vectorial observables.
Finally, I will exemplify these concepts showing analytical and numerical results on the FRs for a Janus particle, i.e. a self-proppelled colloid driven off-equilibrium by asymmetric heating.
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
06.10.2015, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Solutions of adhesive Biopolymers
Cand. M.Sc. Felix Schramm
10.09.2015, time: 12:00h, place: SR 211, ITP
Coupled Brownian motion in a temperature gradient
Asli Abdullahi
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
06.07.2015, time: 15:15h, place: SR 211, ITP
A catch-slip bond model for arbitrary forces and speeds
Dipl. Phys. Jakob Bullerjahn
29.06.2015, time: 15:30h, place: SR 211, ITP
Langevin theory of many-body systems coupled to non-equilibrium environments
M.Sc. Stefano Steffenoni
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
15.06.2015, time: 15:15h, place: SR 211, ITP
Towards a hydrodynamic theory of interactions between Janus particles
M.Sc. Guillermo Zecua
08.06.2015, time: 15:15h, place: SR 211, ITP
On the (non)linear response of systems out of equilibrium
M.Sc. Gianmaria Falasco
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
04.06.2015, time: 11:00h, place: SR 211, ITP
Solutions of adhesive biopolymers
B.Sc. Felix Schramm
01.06.2015, time: 15:15h, place: SR 211, ITP
On viscoelasticity in microrheology
B.Sc. Tim Herpich
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
13.05.2015, time: 14:15h, place: SR 114, ITP
TKM-/FOR 877-Seminar
Optimal paths in a random potential
Prof. Dr. Jan Kierfeld
Abstract
23.04.2015, time: 12:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Brownian motion of anisotropic particles
Dr. Felix Höfling
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
16.04.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
Viscoelastic subdiffusion, transport, and rate processes
in multistable potentials: basic models and applicationsBrownian motion of anisotropic particles
Dr. Igor Goychuk
Past talks (WS 2014/15)
28.01.2015, time: 15:15h, place: SR 114, ITP
Non-Markovian escape processes in cusp potentials
Dipl. Phys. Jakob Bullerjahn
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
22.01.2015, time: 13:00h, place: SR 211, ITP
Mesoscale Modeling of Aeolian Sand Transport
M.Ed. Anne Meiwald
20.01.2015, time: 14:00h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The stochastic thermodynamics of efficiency fluctuations: Exact results and perspectives
Dr. Matteo Polettini
Abstract
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
16.01.2015, time: 11:15h, place: SR 114, ITP
TKM-Seminar
Stochastic Models of Self-propelled Particles
Prof. Dr. Lutz Schimansky-Geier
Abstract
15.01.2015, time: 13:00h, place: SR 211, ITP
Disorder-induced Polymer Bending
Dipl. Phys. Sebastian Sturm
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
08.01.2015, time: 13:00h, place: SR 211, ITP
Coarse-grained Simulations of Dune Field Evolution
Cand. B.Sc. Meike Will
18.12.2014, time: 15:00h, place: SR 114, ITP
Master's thesis defense
Gegenseitige Stabilisierung von Sicheldünen
Cand. M.Sc. Sven Auschra
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
16.12.2014, time: 13:30h, place: SR 211, ITP
Master's thesis defense
MD-Simulationen (heißer) Brownscher Teilchen auf GPUs
Cand. M.Sc. Richard Pfaller
04.12.2014, time: 14:15h, place: SR 211, ITP
TKM-Seminar
Optimaler Massentransport: Einige Anwendungen in Geometrie, Stochastik und Physik
Prof. Dr. Max von Renesse
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
03.12.2014, time: 15:15h, place: SR 114, ITP
Wind-driven sand sorting and structure formation
Dipl. Phys. Marc Lämmel
27.11.2014, time: 13:00h, place: SR 211, ITP
Energy repartition in coupled oscillators subject to heat
fluxes
M.Sc. Gianmaria Falasco
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
06.11.2014, time: 13:00h, place: SR 211, ITP
Two-dimensional models of cell mechanics
B.Sc. Benjamin Streitz
04.11.2014, time: 14:00h, place: SR 113, ITP
TKM-Seminar
When boundaries melt away: flow and arrest in soft
and biological matter
Dr. Claus Heussinger
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
22.10.2014, time: 13:15h, place: SR 211, ITP
A geometrical description of the impact process of particles onto 2D granular packings
B.Sc. Maik Weßling
01.10.2014, time: 11:00h, place: SR 210, ITP
Non-linear mechanics of collagen and fibrin networks
under cyclic large amplitude loading
Dr. Stefan Münster
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
Past talks (SS 2014)
04.08.2014, time: 10:30h, place: SR 210, ITP
How geometry determines cell morphology and tissue growth
cand. M.Sc. Michaela Kettner
15.07.2014, time: 14:00h, place: SR 114, ITP
Kombiniertes schematisches Modell zur Beschreibung inelastischer Effekte an Zellaggregaten
cand. B.Sc. Paul Mollenkopf
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
17.06.2014, time: 14:00h, place: SR 114, ITP
Swarms of active Janus particles
M.Sc. Guillermo Zecua
10.06.2014, time: 11:15h, place: SR 114, ITP
Molecular Integral Equations for the Liquid State
Dr. Nikolaj Georgi
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
02.06.2014, time: 13:00h, place: Brüderstr. 34, kleiner Hörsaal
Workshop Cells & Networks
Download program
27.05.2014, time: 11:00h, place: SR 114, ITP
Measurement of F-actin tube radius fluctuations of different sample history and their orientation distribution in three dimensions
Dipl. Phys. Evelin Jaschinski
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5
TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
19.05.2014, time: 13:30h, place: SR 224, Linnéstr. 5 TKM-/FOR 877-Seminar
Phase separation in active colloids
Prof. Michael E. Cates
13.05.2014, time: 14:00h, place: SR 114, ITP
'Not all those who wander are lost' ... when your itchy feet take you to Israel – a travelogue
M.Ed. Anne Meiwald
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
06.05.2014, time: 13:00h, place: SR 114, ITP
Phoretic swimmers
M.Sc. Guillermo Zecua
08.04.2014, time: 13:30h, place: SR 113, ITP
TKM-/FOR 877-Seminar
The statistics of knots in polymers
Dr. Marco Baiesi
Abstract
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
Past talks (WS 2013/14)
12.02.2014, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
Random tumbling
Prof. Dr. Michael Wilkinson
Abstract
30.01.2014, time: 14:30h, place: SR 211, ITP
Rapid force spectroscopy
Dipl. Phys. Jakob Bullerjahn
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
07.01.2014, time: 13:30h, place: SR 211, ITP
Stability of Barchan Dune Fields
B.Sc. Sven Auschra
07.01.2014, time: 15:00h, place: SR 211, ITP
Modelling of Barchan Dune Fields
B.Sc. Mona Guthardt
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
26.11.2013, time: 14:00h, place: SR 211, ITP
Dusty plasma: problems and applications
M.Sc. Dmitrii Mishagli
19.11.2013, time: 14:30h, place: SR 211, ITP
Hot Brownian motion: measuring the hydrodynamic mode temperature
M.Sc. Gianmaria Falasco
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
30.10.2013, time: 14:00h, place: SR 210, ITP
TKM-/FOR 877-Seminar
The distribution of work performed on a superconductor/normal-metal junction
Jaime Santos, DPhil
Abstract
Past talks (SS 2013)
05.09.2013, time: 13:00h, place: SR 210, ITP
Workshop Cells & Weak Bonds
Download program
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
18.07.2013, time: 14:45h, place: SR 211, ITP
Nematic microstructure in biopolymer solutions
Dipl. Phys. Marc Lämmel
11.07.2013, time: 15:00h, place: SR 211, ITP
Aeolian Sand Transport. The continuum description under scrutiny
B. Sc. Anne Meiwald
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
04.07.2013, time: 14:45h, place: SR 211, ITP
Hot Brownian motion
M. Sc. Gianmaria Falasco
13.06.2013, time: 15:00h, place: SR 211, ITP
Geometry determines cell morphology and tissue growth
B. Sc. Michaela Kettner
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
03.04.2013, time: 11:00h, place: SR 114, ITP
Master's thesis defense
Inelastic mechanics of cells
B. Sc. Matti Gralka
Past talks (WS 2012/13)
21.03.2013, time: 10:00h, place: SR 210, ITP
Stability of dune fields
B. Sc. Sven Auschra
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
21.03.2013, time: 09:00h, place: SR 210, ITP
TBA: Towards Baryoleptonic Asymmetry. Computation of CP
Violating Decays in N2 Leptogenesis
M.Sc. Guillermo Zecua
20.03.2013, time: 11:00h, place: SR 210, ITP
The dynamics and rheology of highly entangled polymers: A study using the Rolie-Poly model
Ewan Henry
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
19.03.2013, time: 14:00h, place: SR 210, ITP
Quantum decision theory
B. Sc. Sajad Saeedi
23.01.2013, time: 15:00h, place: SR 211, ITP
Persistently inconclusive data: polymers in disorder
Dipl. Phys. Sebastian Sturm
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
16.01.2013, time: 15:00h, place: SR 211, ITP
Melting of pectin gels
Dipl. Phys. Andrea Kramer
09.01.2013, time: 15:00h, place: SR 211, ITP
Improved modelling of forced Kramers escape
Dipl. Phys. Jakob Bullerjahn
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
05.12.2012, time: 15:00h, place: SR 211, ITP
Inelastic response of cells to stretch
Cand. M. Sc. Matti Gralka
20.11.2012, time: 11:00h, place: SR 211, ITP
Hot Brownian motion
Dipl. Phys. Daniel Rings
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
14.11.2012, time: 11:15h, place: SR 210, ITP
Computer simulations on hot Brownian particles
Cand. B. Sc. Sven Auschra
07.11.2012, time: 11:15h, place: SR 210, ITP
Grasping the microstructure of F-actin solutions by the tube model
Dipl. Phys. Marc Lämmel
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
Past talks (SS 2012)
12.07.2012, time: 14:00h, place: kleiner Seminarraum
Interpreting dynamic force spectroscopy data
Dipl.-Phys. Jakob Bullerjahn
09.07.2012, time: 13:00h, place: großer Seminarraum
TKM-/FOR877-Seminar
Multiscale mechanical characterization of biological soft matter
Nicholas Agung Kurniawan
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
23.05.2012, time: 11:00h, place: Besprechungsraum, ITP
Thermal effects on passive and active biomechanics of cells
Joseph Chan
24.05.2012, time: 14:00h, place: kleiner Seminarraum
Segmentation of actin filaments from noisy LSM data
Dipl.-Inf. Patrick Scheibe
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
10.05.2012, time: 14:00h, place: kleiner Seminarraum
Effective temperatures for hot Brownian particles with emphasis on the kinetic degrees of freedom
Dipl.-Phys. Daniel Rings
Past talks (WS 2011/12)
08.03.2012, time: 14:30h, place: großer Seminarraum
Long-range interactions in self-propelled particle systems
Gianmaria Falasco
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
27.02.2012, time: 14:00h, place: großer Seminarraum
Tissue mechanics – between liquid and solid
B. Sc. Matti Gralka
19.01.2012, time: 13:00h, place: kleiner Seminarraum
Brownian motion of heated nanoparticles
Dr. Dipanjan Chakraborty
12.01.2012, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
12.01.2012, time: 15:15h, place: SR 221 Joint Seminar MOP/TKM
Power spectral density analysis in magnetic tweezers experiments: From force calibration to friction within DNA structures
Dr. Ralf Seidel
15.12.2011, time: 13:00h, place: kleiner Seminarraum
Memory-controlled reaction kinetics
Dipl. Phys. Sebastian Sturm
01.12.2011, time: 15:15h, place: SR 221
Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
01.12.2011, time: 15:15h, place: SR 221 Joint Seminar MOP/TKM
The interaction between monoclonal antibodies and tau- peptides - how two binding sites add up to form a specific bond
Dipl. Phys. Carolin Wagner
Modelling the forcible separation of noncovalent bonds
Dipl. Phys. Jakob Bullerjahn
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
10.11.2011, time: 13:00h, place: kleiner Seminarraum
Time-symmetric quantum mechanics
Dipl. Phys. Andrea Kramer
20.10.2011, time: 11:00h, place: Besprechungsraum, ITP
A two-species continuum model of aeolian sand transport
Dipl. Phys. Marc Lämmel
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
19.10.2011, time: 13:30h, place: Besprechungsraum, ITP
Sand-induced dust emission
Dipl. Phys. Daniel Rings
Past talks (SS 2011)
20.09.2011, time: 12:15h, place: großer Seminarraum
Inelastische Mechanik von Biopolymernetzwerken und Zellen
Dipl. Phys. Lars Wolff
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
01.09.2011, time: 17:00h, place: großer Seminarraum
Stochastic dynamics simulation of a sticky wormlike chain polymer
Michael Lindon
16.08.2011, time: 14:00h, place: großer Seminarraum
Hot Brownian motion
Hugo Brandao
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
14.07.2011, time: 15:30h, place: kleiner Seminarraum
Inelastic mechanics of biopolymer networks and cells
Dipl. Phys. Lars Wolff
11.07.2011, time: 10:00h, place: großer Seminarraum
FOR877-Seminar
Optical tweezers: wideband microrheology
Dr. Manlio Tassieri
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
24.05.2011, time: 15:00h, place: Besprechungsraum, ITP
Introduction to finite element method
Sandeep Patil
18.05.2011, time: 09:00h, place: kleiner Seminarraum
Joint TKM-/FOR877-Seminar
Critical depletion
Prof. Roberto Piazza
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
12.05.2011, time: 15:30h, place: kleiner Seminarraum
Semiflexible polymer networks
Dipl. Phys. Jens Glaser
11.05.2011, time: 09:00h, place: kleiner Seminarraum
FOR877-Seminar
Directing Brownian motion: Negative mobility and beyond
Dr. Ralf Eichhorn
03.05.2011, time: 12:30h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
03.05.2011, time: 12:30h, place: großer Seminarraum Joint TKM-/FOR877-Seminar
Explosive percolation
Dr. Nuno Araujo
29.04.2011, time: 14:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Mechanosensation of adherent cells
Prof. Sean Sun
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
28.04.2011, time: 15:30h, place: kleiner Seminarraum
Two-species model for aeolian sand transport
Cand. Phys. Marc Lämmel
11.04.2011, time: 13:00h, place: Besprechungsraum, ITP
Fragmentation Rates of Marine Aggregates
Dipl. Phys. David Bastine
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
04.04.2011, time: 15:30h, place: Besprechungsraum, ITP
Biomechanics of cells
Dr. Pablo Fernández
Past talks (WS 2010/11)
21.01.2010, time: 14:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
13.01.2010, time: 15:30h, place: kleiner Seminarraum
Molecular dynamics simulation of isothermal and hot Brownian motion
Dr. Dipanjan Chakraborty
06.01.2010, time: 15:30h, place: kleiner Seminarraum
A binding model for a network of semiflexible polymers
Cand. Phys. Jakob Bullerjahn
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
09.12.2010, time: 15:30h, place: kleiner Seminarraum
Journal Club: The Cross-link Governed Dynamics and its
Relation to the GWLC
Dipl. Phys. Lars Wolff
25.11.2010, time: 15:30h, place: kleiner Seminarraum
Mechanisms & regulation of cortical actin turnover
B. Sc. Steve Simmert
04.11.2010, time: 10:00h, place: großer Seminarraum
Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
04.11.2010, time: 10:00h, place: großer Seminarraum Joint TKM-/FOR877-Seminar
Temperature-modulated cell adhesion
Dr. Félix Rico
22.10.2010, time: 14:00h, place: großer Seminarraum
Too stiff to move - relating cell deformability to cell migration
Dipl. Phys. Franziska Lautenschläger
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
21.10.2010, time: 15:30h, place: kleiner Seminarraum
From stiff polymers to cell mechanics
Dipl. Phys. Jens Glaser
12.10.2010, time: 14:00h, place: Besprechungsraum, ITP
Polymer solutions & networks
Cand. Phys. Marc Lämmel
01.10.2010, time: 11:00h, place: großer Seminarraum
FOR877-Seminar
Tube width fluctuations in F-actin solutions
Dipl. Phys. Inka Lauter
01.10.2010, time: 11:00h, place: großer Seminarraum FOR877-Seminar
Tube width fluctuations in F-actin solutions Dipl. Phys. Inka Lauter
Polymers have versatile physical characteristics. Besides stiff and flexible polymers, the class of semiflexible polymers is of high interest in rheology as well as in biophysics. A model system for semiflexible polymers is filamentous actin (F-actin). Actin is one of the major components of the cytoskeleton in eukaryotic cells. Among other things, they are responsible for the force transduction and generation within a cell and they help the cell to sustain its shape.
In my talk I would like to introduce the experimental part of the cooperation with the group of Prof. Kroy [1]. In this experiment we visualized single fluorescent actin filaments within a solution of unlabeled actin with a laser-scanning-microscope. Driven by thermal energy those filaments fluctuate within the boundary of a tube-like region defined by surrounding filaments. The dimension of this tube can be measured using image processing algorithms. Our interest focuses on the probability distribution of the tube diameter vs. actin concentration in solution.
Furthermore, I will introduce preliminary data on shear measurements of actin solutions from a joined project with the "Institute of soft condensed matter (IFF-7)" (Forschungszentrum Jülich).
[1] J. Glaser, D. Chakraborty, K. Kroy, I. Lauter, M. Degawa, N. Kirchgeßner, B. Hoffmann, R. Merkel, M. Giesen, Phys. Rev. Lett. 105, 037801 (2010)
Past talks (SS 2010)
15.09.2010, time: 09:15h, place: großer Seminarraum
Questions to symmetry breaking in cells and tissues
Prof. Dr. Claus Fütterer
02.09.2010, time: 15:15h, place: großer Seminarraum
Tube width fluctuations in F-actin solutions
Dipl. Phys. Jens Glaser
02.09.2010, time: 14:15h, place: großer Seminarraum
Das Minimal-Model für Dünen und eine Implementierung in Mathematica
Cand. B.Sc. Lukas Kimme
02.09.2010, time: 13:30h, place: großer Seminarraum
Mikrofluidik und stochastische Thermodynamik in lambda-DNA-Lösungen
Dipl. Phys. Olaf Überschär
02.09.2010, time: 10:30h, place: großer Seminarraum
Inelastic mechanics of biopolymer networks
Dipl. Phys. Lars Wolff
14.07.2010, time: 14:00h, place: großer Seminarraum
A Becker-Döring type stochastic particle system
Dipl. Math. André Schlichting
14.07.2010, time: 10:30h, place: großer Seminarraum
Constraint release in polymer networks
Cand. B.Sc. Matti Gralka
17.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Continuum two species saltation model
Cand. Phys. Marc Lämmel
10.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Fractional dynamics vs. fractional Brownian motion
Cand. Phys. Jakob Bullerjahn
03.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Structural damping and breakdown of linear response in biopolymer networks
Dipl. Phys. Lars Wolff
20.05.2010, time: 15:15h, place: Besprechungsraum, ITP
Cool stuff with hot Brownian motion
Dipl. Phys. Daniel Rings
06.05.2010, time: 16:30h, place: großer Seminarraum
Journal seminar
Past talks (WS 2009/10)
08.02.2010, time: 16:30h, place: großer Seminarraum
The conformations of a stiff polymer in quenched random disorder: the replica approach
Dipl. Phys. Marcel Hennes
08.02.2010, time: 15:00h, place: großer Seminarraum
Molecular Dynamics on Graphics Processing Units
Dr. Dipanjan Chakraborty
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
02.09.2010, time: 14:15h, place: großer Seminarraum
Das Minimal-Model für Dünen und eine Implementierung in Mathematica
Cand. B.Sc. Lukas Kimme
02.09.2010, time: 13:30h, place: großer Seminarraum
Mikrofluidik und stochastische Thermodynamik in lambda-DNA-Lösungen
Dipl. Phys. Olaf Überschär
02.09.2010, time: 10:30h, place: großer Seminarraum
Inelastic mechanics of biopolymer networks
Dipl. Phys. Lars Wolff
14.07.2010, time: 14:00h, place: großer Seminarraum
A Becker-Döring type stochastic particle system
Dipl. Math. André Schlichting
14.07.2010, time: 10:30h, place: großer Seminarraum
Constraint release in polymer networks
Cand. B.Sc. Matti Gralka
17.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Continuum two species saltation model
Cand. Phys. Marc Lämmel
10.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Fractional dynamics vs. fractional Brownian motion
Cand. Phys. Jakob Bullerjahn
03.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Structural damping and breakdown of linear response in biopolymer networks
Dipl. Phys. Lars Wolff
20.05.2010, time: 15:15h, place: Besprechungsraum, ITP
Cool stuff with hot Brownian motion
Dipl. Phys. Daniel Rings
06.05.2010, time: 16:30h, place: großer Seminarraum
Journal seminar
Past talks (WS 2009/10)
08.02.2010, time: 16:30h, place: großer Seminarraum
The conformations of a stiff polymer in quenched random disorder: the replica approach
Dipl. Phys. Marcel Hennes
08.02.2010, time: 15:00h, place: großer Seminarraum
Molecular Dynamics on Graphics Processing Units
Dr. Dipanjan Chakraborty
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
02.09.2010, time: 10:30h, place: großer Seminarraum
Inelastic mechanics of biopolymer networks
Dipl. Phys. Lars Wolff
14.07.2010, time: 14:00h, place: großer Seminarraum
A Becker-Döring type stochastic particle system
Dipl. Math. André Schlichting
14.07.2010, time: 10:30h, place: großer Seminarraum
Constraint release in polymer networks
Cand. B.Sc. Matti Gralka
17.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Continuum two species saltation model
Cand. Phys. Marc Lämmel
10.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Fractional dynamics vs. fractional Brownian motion
Cand. Phys. Jakob Bullerjahn
03.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Structural damping and breakdown of linear response in biopolymer networks
Dipl. Phys. Lars Wolff
20.05.2010, time: 15:15h, place: Besprechungsraum, ITP
Cool stuff with hot Brownian motion
Dipl. Phys. Daniel Rings
06.05.2010, time: 16:30h, place: großer Seminarraum
Journal seminar
Past talks (WS 2009/10)
08.02.2010, time: 16:30h, place: großer Seminarraum
The conformations of a stiff polymer in quenched random disorder: the replica approach
Dipl. Phys. Marcel Hennes
08.02.2010, time: 15:00h, place: großer Seminarraum
Molecular Dynamics on Graphics Processing Units
Dr. Dipanjan Chakraborty
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
14.07.2010, time: 10:30h, place: großer Seminarraum
Constraint release in polymer networks
Cand. B.Sc. Matti Gralka
17.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Continuum two species saltation model
Cand. Phys. Marc Lämmel
10.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Fractional dynamics vs. fractional Brownian motion
Cand. Phys. Jakob Bullerjahn
03.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Structural damping and breakdown of linear response in biopolymer networks
Dipl. Phys. Lars Wolff
20.05.2010, time: 15:15h, place: Besprechungsraum, ITP
Cool stuff with hot Brownian motion
Dipl. Phys. Daniel Rings
06.05.2010, time: 16:30h, place: großer Seminarraum
Journal seminar
Past talks (WS 2009/10)
08.02.2010, time: 16:30h, place: großer Seminarraum
The conformations of a stiff polymer in quenched random disorder: the replica approach
Dipl. Phys. Marcel Hennes
08.02.2010, time: 15:00h, place: großer Seminarraum
Molecular Dynamics on Graphics Processing Units
Dr. Dipanjan Chakraborty
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
10.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Fractional dynamics vs. fractional Brownian motion
Cand. Phys. Jakob Bullerjahn
03.06.2010, time: 15:15h, place: Besprechungsraum, ITP
Structural damping and breakdown of linear response in biopolymer networks
Dipl. Phys. Lars Wolff
20.05.2010, time: 15:15h, place: Besprechungsraum, ITP
Cool stuff with hot Brownian motion
Dipl. Phys. Daniel Rings
06.05.2010, time: 16:30h, place: großer Seminarraum
Journal seminar
Past talks (WS 2009/10)
08.02.2010, time: 16:30h, place: großer Seminarraum
The conformations of a stiff polymer in quenched random disorder: the replica approach
Dipl. Phys. Marcel Hennes
08.02.2010, time: 15:00h, place: großer Seminarraum
Molecular Dynamics on Graphics Processing Units
Dr. Dipanjan Chakraborty
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
20.05.2010, time: 15:15h, place: Besprechungsraum, ITP
Cool stuff with hot Brownian motion
Dipl. Phys. Daniel Rings
06.05.2010, time: 16:30h, place: großer Seminarraum
Journal seminar
Past talks (WS 2009/10)
08.02.2010, time: 16:30h, place: großer Seminarraum
The conformations of a stiff polymer in quenched random disorder: the replica approach
Dipl. Phys. Marcel Hennes
08.02.2010, time: 15:00h, place: großer Seminarraum
Molecular Dynamics on Graphics Processing Units
Dr. Dipanjan Chakraborty
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (WS 2009/10)
08.02.2010, time: 16:30h, place: großer Seminarraum
The conformations of a stiff polymer in quenched random disorder: the replica approach
Dipl. Phys. Marcel Hennes
08.02.2010, time: 15:00h, place: großer Seminarraum
Molecular Dynamics on Graphics Processing Units
Dr. Dipanjan Chakraborty
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
08.02.2010, time: 11:00h, place: großer Seminarraum
GPU-accelerated Browninan Dynamics of effective
stiff polymer solutions
Dipl. Phys. Jens Glaser
27.01.2010, time: 15:00h, place: kleiner Seminarraum
Escape over a barrier: Hazard function and
Fokker-Planck equation
Cand. Phys. Jakob Bullerjahn
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
20.01.2010, time: 15:00h, place: kleiner Seminarraum
Tube Width Fluctuations in F-Actin Solutions
Dipl. Phys. Jens Glaser
01.12.2009, time: 10:00h, place: Besprechungsraum
Nonlinear mechanics of Actin-HMM solutions
Dipl. Phys. Lars Wolff
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
07.10.2009, time: 11:15h, place: kleiner Seminarraum
Nonlinear cell mechanics is inelastic mechanics
Dipl. Phys. Lars Wolff
07.10.2009, time: 10:30h, place: kleiner Seminarraum
Nonequilibrium GWLC dynamics
Dipl. Phys. Sebastian Sturm
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (SS 2009)
08.07.2009, time: 16:00h, place: kleiner Seminarraum
The conformations of stiff polymers in random media
Cand. Phys. Marcel Hennes
17.06.2009, time: 16:00h, place: kleiner Seminarraum
Hot Brownian motion
Dipl. Phys. Daniel Rings
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
10.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part II)
Dipl. Phys. Jens Glaser
03.06.2009, time: 16:00h, place: kleiner Seminarraum
Tube model and Brownian dynamics of tightly entangled stiff polymers (part I)
Dipl. Phys. Jens Glaser
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
20.05.2009, time: 16:00h, place: kleiner Seminarraum
Nonlinear Cell Mechanics
Dipl. Phys. Lars Wolff
13.05.2009, time: 16:00h, place: kleiner Seminarraum
Semiflexible polymers in random potentials
Dipl. Phys. Sebastian Schöbl
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
06.05.2009, time: 16:00h, place: kleiner Seminarraum
Trap models & slow relaxation
Dipl. Phys. Sebastian Sturm
29.04.2009, time: 16:00h, place: kleiner Seminarraum
Localization of maximal entropy random walk
Dr. Bartlomiej Waclaw
We define a new class of random walk processes which maximize entropy. This
maximal entropy random walk is equivalent to generic random walk if it takes
place on a regular lattice, but it is not if the underlying lattice is
irregular. In particular, we consider a lattice with weak dilution. We show
that the stationary probability of finding a particle performing maximal
entropy random walk localizes in the largest nearly spherical region of the
lattice which is free of defects. This localization phenomenon, which is
purely classical in nature, is explained in terms of the Lifshitz states of
a certain random operator. A connection to Feynman path-integral approach to
quantum mechanics is also shown.
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
15.04.2009, time: 16:00h, place: kleiner Seminarraum
Persistence in Stochastic Processes
Dipanjan Chakraborty, PhD
08.04.2009, time: 14:00h, place: Linnestr., S228
Joint seminar TKM/PWM
Anomalous dynamics of cell migration
Dr. Rainer Klages
Cell movement, for example, during embryogenesis or tumor metastasis, is a
complex dynamical process resulting from an intricate interplay of multiple
components of the cellular migration machinery. At first sight, the paths of migrating
cells resemble those of thermally driven Brownian particles. However, cell migration
is an active biological process putting a characterization in terms of normal Brownian
motion into question. By analyzing the trajectories of wild-type and mutated epithelial
(transformed Madin-Darby canine kidney) cells, we show experimentally that
anomalous dynamics characterizes cell migration. A superdiffusive increase of the
mean squared displacement, non-Gaussian spatial probability distributions, and
power-law decays of the velocity autocorrelations are the basis for this interpretation.
Almost all results can be explained with a fractional Klein-Kramers equation allowing
the quantitative classification of cell migration by a few parameters.
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (WS 2008/09)
4.3.2009, time: 09:30h, place: großer Seminarraum
Symposium
see program for details
11.12.2008, time: 14:00h, place: kleiner Seminarraum
Collective effects in systems of coupled hair bundles
Dipl. Math. Kai Dierkes
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (SS 2008)
22.09.2008, time: 13:00h, place: kleiner Seminarraum
Adsorption of a semi-flexible polymer on a rigid membrane
Maryam Aliee
We present static as well as dynamical approach to study the behavior of an adhering
semi-flexible filament, like microtubule, interacting with a rigid membrane. Analyzing the
detailed microscopic model for the adhesion problem, we study the dynamics of such a
polymer in different cases, where either a fixed force or a fixed height is applied at its end.
We can show that in the force ensemble a critical force is expected. Forces smaller than the
critical value are not able to peel off the filament, while the larger forces will cause the
filament to completely detach from the membrane. To demonstrate the nonequilibrium
properties of the moving states for forces larger than the critical value, we present the linear
response of the system in the form of a force velocity relation.
In addition, by studying the phenomenological static model with short range
interactions, we obtain the equilibrium phases of the system in different cases. The results
are in good agreement with the results observed by the dynamical microscopic model.
21.07.2008, time: 11:00h, place: kleiner Seminarraum
Glassy Tension Propagation
Cand. Phys. Sebastian Sturm
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
08.07.2008, time: 11:00h, place: Besprechungsraum ITP
Retrokausation
Cand. Phys. Andrea Kramer
10.06.2008, time: 14:00h, place: kleiner Seminarraum
Koordination Wissenschaftssommer
Arbeitsgruppe
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
03.06.2008, time: 14:00h, place: kleiner Seminarraum
Übersicht ueber laufende Kooperationen
Dipl. Phys. Jens Glaser
27.05.2008, time: 14:00h, place: kleiner Seminarraum
Round-Table-Seminar: Entanglement
Prof. Dr. Klaus Kroy
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
06.05.2008, time: 14:00h, place: kleiner Seminarraum
Einfluss von HMM auf Aktinlösungen
Cand. Phys. C. Hubert
24.04.2008, time: 11:00h, place: kleiner Seminarraum
2D barchan dunes made in the lab
Dipl. Phys. Christopher Groh (Uni Bayreuth)
For a long time people are fascinated by the dynamics of sand
dunes. And so it is not surprising that there are a lot of field
studies, which give an overview about the facts of the formation of
dunes in the desert or at the beach. In recent years scientists
looked for theoretical models to give answers to the basic
questions of the physical mechanisms of dune formation and
migration. In our setup we are able to investigate a well defined
two-dimensional single barchan dune under the force of a shearing
water flow. Thus we have a basic access to the dynamics of a
barchan dune. This allows easily the validation of the existing
two-dimensional theoretical models with our experimental data.
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
15.04.2008, time: 11:15h, place: kleiner Seminarraum
Impact of disorder on semiflexible polymer conformations
Dipl. Phys. S. Schöbl
10.04.2008, time: 09:15h, place: kleiner Seminarraum
Turbulence and Aeolian Sand Transport
Dr. H.-J. Schönfeldt
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (WS 2007/08)
31.1.2008, time: 11:00h, place: kleiner Seminarraum
Dislocation tangles und Aktin-Netzwerke
Dipl. Phys. L. Wolff
17.1.2008, time: 11:00h, place: kleiner Seminarraum
Theorie der dynamischen Lichtstreuung semiflexibler Polymere
Dipl. Phys. J. Glaser
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
12.12.2007, time: 13:30h, place: großer Seminrraum ITP
Rheological Properties of Nano-Fiber Networks
Prof. Dr. Christian Friedrich (Uni Freiburg)
The dispersion of nano-fibers (nm-thick and μm-long fibers) in matrices, without
bundling or aggregation, is of crucial importance for the beneficial combination of
fiber properties with those of matrix fluids. For two different fiber systems - pre-made
fibers such as multi-walled carbon nanotubes (CNT) or fibers that are formed during a
self-assembling process in the matrix (SAF) - dispersed in different matrices (different
chemical nature, high and low molecular weights), we dealt with methods enabling good
dispersion of the fibers in the corresponding matrices and characterization of the
dispersion properties. We identified the concentration regions in which network
formation is dominant for the different systems and determind the linear and nonlinear
thermo-rheological properties of the fiber networs. We found that, regardless of the
chemical nature of the fibers, the rheological properties of the tightly entangled
fiber networks possess some unique characteristics. Using models developed for
semiflexible biopolymer networks, we can understand the obtained results quantitatively.
22.11.2007, time: 11:00h, place: kleiner Seminarraum
Eine Erweiterung des Doi-Kuzuu-Modells
Cand. Phys. S. Grosser
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
25.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles (part II)
Dipl. Phys. D. Rings
Modelling Hard Sphere Solutions
Cand. Phys. S. Schöbl
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
18.10.2007, time: 11:00h, place: kleiner Seminarraum
Modelling Turbulent Flow with Immersed Inertial Particles
Dipl. Phys. D. Rings
11.10.2007, time: 11:00h, place: kleiner Seminarraum
Dynamic light scattering of crosslinked actin networks
Dipl.-Phys. W. Michel (Uni Bayreuth)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (SS 2007)
13.7.2007, time: 9:15h, place: kleiner Seminarraum
Semiflexible Polymere in Zufallspotentialen
S. Schoebl
4.7.2007, time: 13:30h, place: SR 221
Disorder, replicas and all that
Dr. A. Klopper
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
27.6.2007, time: 13:30h, place: SR 229
Particles in random flows (2)
Dipl. Phys. D. Rings
21.6.2007, time: 9:15h, place: kleiner Seminarraum
The Glassy Wormlike Chain
Dipl. Phys. J. Glaser
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
24.5.2007, time: 9:15h, place: kleiner Seminarraum
Photothermal detection of single nanoobjects
Dipl. Phys. R. Radünz (Department of Molecular
Nano-Photonics)
10.5.2007, time: 9:15h, place: kleiner Seminarraum
Particles in random flows
Dipl. Phys. D. Rings
Joint seminar with
Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Joint seminar with Experimental Soft matter group
8.5.2007, time: 15:00h, place: kleiner Seminarraum
Shape oscillations in non-adhering fibroblast cells
Dr. Pramod Pullarkat (University of Bayreuth)
3.5.2007, time: 9:00h, place: kleiner Seminarraum
Swimming and Chemotaxis of Sperm Cells
Dipl. Math. B. Friedrich (MPI PKS Dresden)
Sperm cells swim towards the egg propelled by a flagellum which beats
regularly.
In many species sperm show chemotaxis, i.e. they move upwards a
gradient of chemoattractant molecules released by the egg.
Based on recent experiments on sea urchin sperm which indicate that
the geometry of swimming trajectories is controlled by a signaling
system in the sperm flagellum [1], we present a theoretical
description of sperm chemotaxis.
In a first part of my talk, I will discuss swimming trajectories in
two and three dimensions in the presence of a chemoattractant source.
> From this discussion, I derive the necessary properties of the
signaling system which ensure reliable motion towards the source.
In a second part of the talk, I want to present some preliminary results
on the hydrodynamics of flagellar propulsion and demonstrate that
circular swimming is a direct consequence of the asymmetry of the
flagellar beat.
[1] B. Kaupp et al.: NCB 5,109 (2003)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (WS 2006/07)
7.3.2007, time: 14:00h, place: großer Seminarraum
Dynamics of F-Actin in network solutions
Dr. M. Degawa (FZ Jülich)
The rigidity and dynamical properties of the cell cytoskeleton are
determined
by a 3D network of polymerized one-dimensional protein filaments,
one of which is the actin filament (F-actin). The understanding
of the thermodynamics of F-actin filaments is crucial for cell biophysics,
specially within such a network. Whereas isolated F-actin is well described
by the worm-like chain model [1], knowledge of thermodynamic
properties of F-actin in networks is still scarce. Here we present first
studies of F-actin within a 3D network where the presence of other
filaments serves as an entropic constraint. We used partially TRITClabeled
networks of different concentration. The fluctuations of the
labeled filaments were visualized with line-scan confocal scanning
microscopy time images with a time resolution of 1 ms. We measure the
time dependence of the filament fluctuations, which yield a concentration
dependence of the crossover time in the time correlation function
from isolated to constrained behavior of the individual F-actin.
[1] L. Le Goff, O. Hallatschek, E. Frey, F. Amblard, Phys. Rev. Lett. 89,
258101 (2002)
19.2.2007, time: 10:00h, place: kleiner Seminarraum
Der Weg zur Neugebauer-Meinel-Lösung
Dipl.-Phys. T. Kiefer (Uni Jena)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
8.2.2007, time: 09:15h, place: kleiner Seminarraum
Strömungsberechnung und Parameteroptimierung mit Hilfe von
integrierter Modellierungs- und Simulationssoftware
Dr. T. Slawig (TU Berlin)
7.2.2007, time: 14:00h, place: großer Seminarraum
Untangling polymer systems: Structure prediction in
polymer networks with quenched disorder
Dr. A. Klopper (MPI PKS Dresden)
Highly concentrated liquids comprising long polymeric chains can undergo
processes of cross-linking and entanglement, giving rise to intriguing
macroscopic properties. The key ingredient is connective quenched disorder,
which freezes the topology of the liquid in the form of a polymer network.
The translational invariance in the system is spontaneously broken and the
phase space is divided into disjoint ergodic regions.
Such behaviour is well-known from a large class of systems exhibiting the
so-called glassy phase, characterised by randomness and slow dynamics. This
opens the door to an extensive analytic formalism for structure prediction
in cross-linked polymer systems. By constructing a theoretical framework
which makes use of simulation data, one can draw from these techniques
without resorting to microscopic detail and otherwise unphysical
assumptions. In the study presented, the spin-glass replica formalism is
applied to data from molecular dynamics simulations of ideal
non-interacting cross-linked polymer systems in order to describe neutron
scattering measurements in interacting systems.
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
25.1.2007, time: 09:15h, place: kleiner Seminarraum
Journal Club: Anderson-Lokalisierung
Dipl.-Phys. J. Glaser
Joint seminar with Experimental
Soft matter group
17.11.2006 (Friday), time: 09:00h, place: SR 221
Simulation of Shear-driven Aggregation
Dipl.-Phys. D. Rings
We study a two-dimensional toy model of a colloidal suspension
under shear stress. The rather novel simulation method of
collision-driven dynamics has been implemented together with
powerful interval arithmetics. This approach provides means
to study the liquid-gel phase transition in terms
of:
cluster and system structure
cluster size distribution
time until gelation
Effects are interpreted as crossover from kinetic aggregation to
percolation theory.
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem
Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
14.11.2006 (Tuesday), time: 13:00h, place: kleines Konferenzzimmer neben dem Sekretariat, ITP
Nonlinear Elasticity of Entangled Actin Networks
Dipl.-Phys. C. Semmrich (TU München)
The strain hardening of crosslinked actin networks is currently attracting
lots of attention as a paradigm for essential mechanical properties of living
cells. The elasticity of such crosslinked networks can vary by more than one
order of magnitude in dependence of the applied stress. This has been
attributed to the nonlinear mechanical behaviour of single filaments.
In contrast, the mechanical response of purely entangled actin is often
reported to be shear thinning. By means of different rheological approaches
we are able to investigate the nonlinear response of purely entangled actin
networks. Interestingly, under standard conditions a reversible strain
hardening occurs below a critical temperature while above this critical
temperature strain softening is reported. Moreover, this transition
is highly dependent on the buffer salt concentration. We suggest a
simple theoretical model based on the interaction potential between
single actin filaments including temperature and salt dependent effects to
rationalize this behaviour.
26.10.2006, time: 9:15h, place: kleiner Seminarraum
Sandtransport - Messungen und numerische Modellierung
Dr. H.-J. Schönfeldt (Inst. f. Meteorologie, Universität Leipzig)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Past talks (SS 2006)
09.05.2006, time: 10:00h, place: kleiner Seminarraum
Shear driven aggregation in two dimensions
Daniel Rings
Aggregation of colloids has an impact on various technical as well as
biological systems. Consider for example the accumulation of dust in
bearings, or the clotting within blood vessels.
As a toy model we study a two-dimensional colloidal suspension under
shear stress using the method of event- (collision-) driven dynamics
simulation. This rather novell approach provides means to study the
liquid-gel phase transition characterized by a jammed state of the
system after a finite time. The fractal structure of the spanning
cluster is analyzed and interpreted in terms of a crossover from
kinetic aggregation to percolation theory.
Joint seminar with Experimental
Soft matter group
05.05.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Nonlinear viscoelasticity of single fibroblasts
Pablo Fernandez (Universität Bayreuth)
We perform single-cell uniaxial stretching experiments on
3T3 fibroblasts. We show that two separate regimes can be
discerned as a function of deformation amplitude: a
viscoelastic regime at stretches below 10%, and a plastic
one beyond.
We probe the viscoelastic regime by superimposing small
amplitude oscillations to controlled deformations, thus
measuring dynamic elastic moduli as a function of the
average force and cell length. We find a transition from
linear elastic behavior to power-law stress stiffening.
Data from different cells over several stress decades can
be uniquely scaled to obtain a master-relation between the
viscoelastic moduli and the average force. Remarkably, this
relation holds independently of deformation history: it is
irrelevant whether force is actively generated by the cell
or externally imposed by stretching.
Based on the agreement with the mechanical properties of
biopolymer networks, we propose that the master-relation
reflects the passive mechanics of the force-bearing actin
cytoskeleton.
In the plastic regime at large deformations, force and
length are roughly linearly related. A weak rate-dependence
reminds of classic strain-hardening in
plastic materials.
Joint seminar with Experimental
Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
Joint seminar with Experimental Soft matter group
21.04.2006, time: 9:15h, place: Linnéstr. 5, SR 221
Confocal microscopy of attractive colloids: Gelation, Aggregation
and Phase separation
Peter J. Lu (Harvard)
Using the image data from real-time confocal microscopy, I
propose a general framework for the equilibrium phase behavior, and
kinetic state behavior, of attractive colloid-polymer mixtures. Varying
the amount of colloid, and amount and size of the polymers, we observe a
number of phases, states and behaviors. By considering the characteristic
timescales during which colloids aggregate, bond and rearrange, these
different phases and large-scale behaviors may be understood to result
from different combinations of the same microscopic processes.
Past talks (WS 2005/06)
09.02.2006, 11 am, kleiner Seminarraum
Localization Transition and Dynamic Scaling of the 3D Lorentz Model
Felix Höfling
The Lorentz model has served as a paradigm for transport in disordered media. Its simplest variant describes a structureless test particle moving through a random array of identical obstacles. The latter interact with the test particle via a hard-sphere repulsion. At high obstacle densities, the model exhibits a localization transition, i. e., above a critical density, the particle is always trapped by the obstacles. It has been conjectered that the dynamics close to the critical density can be mapped to the transport properties of contiunuum percolation ("Swiss cheese model").
We present extensive Molecular Dynamics simulation and provide unambiguous evidence for an intimate connection between the Lorentz model and continuum percolation. In particular, excellent matching of both the critical density and exponents is obtained. The quality of our data allows to go beyond determining critical exponents, and to give a full analysis of the dynamic scaling properties. We demonstrate the validity of a generalized dynamic scaling theory for the van Hove self-correlation function employing two divergent length scales. The presence of these two length scales manifests itself in a divergence for the non-Gaussian parameter close to the transition.
cond-mat/0510442
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
02.02.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 2
Steffen Arnrich
see 19. 01. 2006
26.01.2006, 11 am, kleiner Seminarraum
Non-Affine Deformations: the "Elementary Excitations" in Random Fiber Networks
Claus Heussinger
We study the elasticity of random fibrous networks in two dimensions. Highly non-affine deformations on the scale of the single fiber are found to lead to anomalous elastic properties even on the macroscopic scale. Our findings have to be contrasted with classical elasticity theory where material elements are supposed to deform in an affine way and microstructure is not accounted for. Starting from the characteristic features of the microscopic deformation field we can calculate macroscopic quantities like the shear modulus.
Our work highlights the importance of architecture to the elastic response of fibrous structures and applies to diverse physical systems ranging from paper sheets to biological networks of semiflexible polymers like the cytoskeleton.
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
19.01.2006, 11 am, kleiner Seminarraum
Ein Modell f�r
Phasenüberg�nge in Kristallen mit nichtlinearer Elastizit�t, Teil 1
Steffen Arnrich
Betrachtet wird die Elastizitätstheorie von Kristallen, deren freie Energiedichte von der lokalen Teilchenkonzentration eines oder mehrerer im Kristall vorkommender Moleküle in einer Weise abhängt, daß je nach Konzentration verschiedene Gittergeometrien (Phasen) bevorzugt werden.
Die lokale Konzentration der einzelnen Molekülsorten ändert sich durch Diffusion, wobei die Zeitskalen für den Konzentrationsausgleich und die Anpassung der Deformation unterschiedlich sind. In erster Näherung ist es zulässig, anzunehmen, daß sich der Deformationsausgleich unendlich schnell einstellt, also instantan erfolgt. Desweiteren wird die Evolution des Randes als gegeben angenommen. Weitere Annahmen sind, daß der Kristall keine Zwischengitterplätze (interstials) besitzt und der Prozeß bei konstanter Temperatur abläuft. Es wird ein mathematisches Modell vorgestellt, welches solche Prozesse beschreibt und explizit die Oberflächenenergie der Phasengrenzflächen berücksichtigt. Zunächst wird eine Lösung für die implizit zeitdiskretes Modellgleichungen vorgestellt und anschlie�end ein Ausblick auf die Lösung des zeitkontinuierlichen Falles gegeben.
15.12.2005, 11 am, kleiner Seminarraum
Dynamic structure factor of semiflexible polymers
Jens Glaser
The minimal model for the statics and dynamics of stiff polymers such as DNA and the polymers of the cytoskeleton is the wormlike chain. With this model, the dynamic structure factor for a single chain is discussed, which contains information about the thermal fluctuations of the polymer in a solvent. It is determined by internal bending dynamics. For extracting consistent and reliable values for the model parameters (persistence length and the backbone thickness), inclusion of hydrodynamics interactions is relevant. The results are compared to recent light scattering experiments, e.g. for actin.
24.11.2005, 11 am, kleiner Seminarraum
Stretching stretched chains
Benedikt Obermayer
Many important biopolymers are accurately described
by the wormlike chain model. A stretching force applied at the
ends of such an inextensible chain induces backbone tension that
spreads into the bulk. Various scaling laws have been proposed
[1-3]
concerning the propagation speed of this tension, based on
different (contradicting) heuristic arguments. A newly developed
unified picture [4] allows to systematically substantiate,
restrict
and extend these approximations. Introducing the general scenario
of a chain equilibrated under some prestretching force
fpre that is suddenly exposed to a different
external force fext at the ends, we give a
concise explanation of the dominant relaxation mechanisms
and proceed towards a full characterization of the dynamic
longitudinal response of stiff polymers and stretched
(semi)flexible filaments.
[1] Seifert, Wintz, Nelson, PRL 77:5389 (1996)
[2] Brochard, Buguin, de Gennes, EPL 47:171 (1999)
[3] Everaers, Jülicher, Ajdari, Maggs, PRL 82:3717 (1999)
[4] Hallatschek, Frey, Kroy, PRL 94:077804 (2004)
24.11.2005, 11 am, kleiner Seminarraum