Anomalous velocity distributions in active Brownian suspensions

摘要

Large-scale simulations and analytical theory have been combined to obtain the nonequilibrium velocitydistribution, f (v), of randomly accelerated particles in suspension. The simulations are based on an event-drivenalgorithm, generalized to include friction. They reveal strongly anomalous but largely universal distributions,which are independent of volume fraction and collision processes, which suggests a one-particle model shouldcapture all the essential features. We have formulated this one-particle model and solved it analytically in thelimit of strong damping, where we find that f (v) decays as 1/v for multiple decades, eventually crossing over toa Gaussian decay for the largest velocities. Many particle simulations and numerical solution of the one-particlemodel agree for all values of the damping.