paper

Toward the full short-time statistics of an active Brownian particle on the plane

arXiv:2004.13547 · doi:10.1103/PhysRevE.102.022113

Abstract

We study the position distribution of a single active Brownian particle (ABP) on the plane. We show that this distribution has a compact support, the boundary of which is an expanding circle. We focus on a short-time regime and employ the optimal fluctuation method (OFM) to study large deviations of the particle position coordinates and . We determine the optimal paths of the ABP, conditioned on reaching specified values of and , and the large deviation functions of the marginal distributions of , and of . These marginal distributions match continuously with "near tails" of the and distributions of typical fluctuations, studied earlier. We also calculate the large deviation function of the joint and distribution in a vicinity of a special "zero-noise" point, and show that has a nontrivial self-similar structure as a function of , and . The joint distribution vanishes extremely fast at the expanding circle, exhibiting an essential singularity there. This singularity is inherited by the marginal - and -distributions. We argue that this fingerprint of the short-time dynamics remains there at all times.

12 pages including 8 figures

References in corpus (3)

Cited by in corpus (22)