News — Views — Research Highlights

Seminar Patterns of Earth

In the winter term 2019/20 I will offer a seminar on Earth Patterns, where we will discuss pattern formation in the geological and geophysical settings.

Fundamentals. Fluid Dynamics, Pattern Formation, Scaling and Self-Similarity
Drainage Divides, Coast Lines
Phase Transitions. Melting, Freezing, Segregation
Cloud Formation, Rain Initiation, Gysers, Minerals, Stalactites and Iciclies
Transport. Multiphase Flow, Plastic Flow, Granular Flow, Porous Media
Sediment Beds, Sand Dunes and Ripples, Glaciers, Lava Flows, Land Slides and Avalanches
Ground Water, Oil Production, Deep-Sea Thermal Vents
Shaping the Surface.      Fracture Dynamics, Avaraging and Long-Time Dynamics
Faults and Cracks, Subduction, Plate Tectonics, Weathering, Sea Ice Dynamics, Large Scale Ocean and Air Flows
Exoplanets.      Thermodynamics, Universality
Climate, Weather, Surface Structures

We aspire to give out topics to tandems of a physics student and a student with a geoscience-background.

Please circulate the announcement poster to prospective participants, and contact me or Klaus Kroy or Annett Krüger to arrange a contribution.

New Paper in Nonlinearity

Equivalence of position–position auto-correlations in the Slicer Map and the Lévy–Lorentz gas
Giberti, Rondoni, Tayyab, and Vollmer, Nonlinearity 32:2302 (15 May 2019)

The Slicer Map (SM) is a one-dimensional non-chaotic dynamical system that shows sub-, super-, and normal diffusion as a function of its control parameter. In a recent paper (Salari et al 2015 Chaos 25 073113) it was found that the moments of the position distributions as the SM have the same asymptotic behaviour as the Lévy–Lorentz gas (LLg), a random walk on the line in which the scatterers are randomly distributed according to a Lévy-stable probability distribution. Here we derive analytic expressions for the position–position correlations of the SM and, on the ground of this result, we formulate some conjectures about the asymptotic behaviour of position–position correlations of the LLg, for which the information in the literature is minimal. The numerically estimated position–position correlations of the Lévy–Lorentz show a remarkable agreement with the conjectured asymptotic scaling.

See the article outline for more information.

Jürgen Vollmer is appointed professor in Leipzig

On 1 February 2019 I have been appointed as a

at the University of Leipzig

Plenary Talk at the workshop DSABNS

The 10th International Conference Dynamical Systems Applied to Biology and Natural Sciences (DSABNS) addresses theoretical methods and practical applications in population dynamics, eco-epidemiology, epidemiology of infectious diseases, molecular and antigenic evolution and methodical topics in the natural sciences and mathematics.

At the workshop I will give a plenary talk on

Domain Drift and Cell Polarization Processes

Seminar Physics of Music

In the winter term 2018/19 I will offer a seminar on Physics of Music, where we will discuss different aspects of music, sound generation and sound processing. The topics will cover

Fundamentals. from Pythagorean harmonics to well-tempered scales
about hearing and singing
Reproduction. from shellac to MP3
about theremins, drum maschines, and synthezising music
Vibrations. singularities on picked and bowed strings
can you hear the shape of a drum?
amplification and locking in resonance cavities
from the singing saw to the modern violin
Compressible Flows.      from sound waves to music
from pipes to trumpets and clarinets

There is ample room for topics where participants do research on their own instruments! Please contact me or Klaus Kroy as soon as possible to arrange a contribution.

Jürgen Vollmer moves to Leipzig

In April 2018 I start my new position as a

Senior Scientist
Institute for Theoretical Physcis
University of Leipzig
with a new homepage

New Paper in Nature Communications

Characterizing rare fluctuations in soft particulate flows
Rahbari, Saberi, Park, and Vollmer, Nature Communications 8:11 (10 April 2017)

Soft particulate media include a wide range of systems involving athermal dissipative particles both in non-living and biological materials. Characterization of flows of particulate media is of great practical and theoretical importance. A fascinating feature of these systems is the existence of a critical rigidity transition in the dense regime dominated by highly intermittent fluctuations that severely affects the flow properties. Here, we unveil the underlying mechanisms of rare fluctuations in soft particulate flows. We find that rare fluctuations have different origins above and below the critical jamming density and become suppressed near the jamming transition. We then conjecture a time-independent local fluctuation relation, which we verify numerically, and that gives rise to an effective temperature. We discuss similarities and differences between our proposed effective temperature with the conventional kinetic temperature in the system by means of a universal scaling collapse.

See our press release and article outline for more information.

Plenary Talk at the symposium Wintersporttribologie

In parallel to the European Symposium on Friction, Wear, Wear Protection and Related Areas there will be a symposium on friction in winter sports (in German). It will address scientific issues in a way that is accessible to interested sport practitioners.

I will contribute the presentation

Eislaufen und Reibung auf Eis

Plenary Talk at the workshop DSABNS

The Eighth Workshop Dynamical Systems Applied to Biology and Natural Sciences (DSABNS) will address theoretical methods and practical applications in population dynamics, eco-epidemiology, epidemiology of infectious diseases, molecular and antigenic evolution and methodical topics in the natural sciences and mathematics.

At the workshop I will give a plenary talk on

Quasi-tight coupling:
When do we see it?
When would we expect to see it?

Participating in the program Nonequilibrium processes at the nanoscale at the KITPC-CAS

On invitation of the Kavli Institute for Theoretical Physics China at the Chinese Academy of Sciences(KITPC-CAS) I spend August 2016 in Beijing to participate in the above workshop. The institute also supports the visit of my Masters student Thomas Staudt.

On August 17 Thomas presents a plenary lecture on our joint work

The continuum limit of the Becker-Döring Equations

On August 25 I deliver a plenary lecture on

Quasi-tight coupling far from equilibrium

Jürgen Vollmer moves to Torino

In August 2016 I start my new position

Distinguished Visiting Professor
Politechnico di Torino
with a new homepage

Inauguration of Web Pages for Teaching Mathematics

Our web pages on Teaching with Mathematical Models and Instruments are launched at the

13th International Congress on Mathematical Education
Hamburg, July 24–31, 2016

Plenary Talk at Dynamics Days 2016

Dynamics Days Europe is a series of major international conferences founded in the 1980's that provides a European forum for developments in the applications of and theory for dynamics.

At the 2016 conference I give a plenary talk on

Breaking Universality in Non-Equilibrium Statistical Physics

Auch das ist Mathematik

We offer an afternoon project Introduction to 3d printing at the Theodor-Heuss Gymnasium, Göttingen

  • introduction to STL files
  • printing example models
  • applications of 3d printing
  • homework: build your own model – the best will be printed!

Invited Talk at the international workshop Two-Phase Continuum Models for Geophysical Particle-Fluid Flows, MPI PKS, Dresden

The program is intended to accelerate advances in the understanding of particle-fluid interactions and the modification of particle-particle interactions in the presence of a fluid. It brings together physicists and experts on geological processes and morphology.

On March 15 I give a plenary talk on

Growth of rain droplets in exotic environments: diffusion, sedimentation, and droplet collection