EventDetails

Speaker:
Prof. Dr. Thomas Voigtmann, Deutsches Zentrum für Luft- und Raumfahrt, Köln

Inspired by biological systems, systems of self-propelled colloidal particles have gained increasing attention of the statistical-physics community. These particles possess some way of converting energy into directed swimming motion, so that they form systems that are intrinsically far from thermal equilibrium. Their collective dynamical behavior is governed by a complex interplay between stochastic thermal fluctuations, entropic forces due to steric hindrance, and "active" directed motion. A clean model system to study this interplay is defined by active Brownian hard-sphere particles (ABP). I will discuss our approach to describe the high-density dynamics of ABP by a mode-coupling theory based on the integration-through transients framework to derive expressions for the non-equilibrium transport coefficients of driven systems. The theory describes kinetically arrested "active glasses" at high densities, and it allows to calculate from first principles some coarse-grained parameters that enter mesoscopic theories to describe the non-equilibrium phases of ABP, specifically a clustering phenomenon termed "motility-induced phase separation (MIPS)". I will also briefly describe simulations and experiments describing light scattering of microswimmers in microgravity.