Dynamical aggregation of self-propelled colloidal particles
Final Report Abstract
In the reporting period, we performed computer simulations on the dynamics of self-propelled particles. The fundamental question here is to what extent classical nonequilibrium systems resemble equilibrium systems with the goal in mind to develop contributions to a (still incomplete) theory of nonequilibrium. An important question in this context is the behavior of the system near a critical point, i.e., the point in the phase diagram at which a (2nd order) transition from an ordered to a disordered phase occurs. In previous works we have studied static behavior and determined critical exponents. For Active Brownian Particles (ABPs) we noticed large deviations from the expected 2d Ising behavior, while for active lattice models only small (but significant) differences were observed. Last year, we have investigated the relaxation of ABPs and several active lattice models after a quench from the disordered to the two-phase region and directly to the critical point. While nonequilibrium dynamics and "aging" are consistent with the expected Ising behavior for ABPs, deviations occur for active lattice models and quenches deep into the two-phase region.
