# Ralf Schützhold

# Emergent horizons in the laboratory

** Abstract: **

The concept of a horizon known from general relativity describes the loss of
causal connection and can be applied to non-gravitational scenarios such as
out-of-equilibrium condensed-matter systems in the laboratory. This analogy
facilitates the identification and theoretical study (e.g., regarding the
trans-Planckian problem) and possibly the experimental verification
of 'exotic' effects known from gravity and cosmology, such as Hawking
radiation. Furthermore, it yields a unified description and better
understanding of non-equilibrium phenomena in condensed-matter systems and
their universal features. By means of several examples including general
fluid flows, expanding Bose-Einstein condensates and dynamical quantum phase
transitions, the concepts of event, particle and apparent horizons will be
discussed together with the resulting quantum effects.