A self-propelled particle in an external potential: is there an effective temperature?
Abstract
We study a stationary state of a single self-propelled, athermal particle in linear and quadratic external potentials. The self-propulsion is modeled as a fluctuating force evolving according to the Ornstein-Uhlenbeck process, independently of the state of the particle. Without an external potential, in the long time limit, the self-propelled particle moving in a viscous medium performs diffusive motion, which allows one to identify an effective temperature. We show that in the presence of a linear external potential the stationary state distribution has an exponential form with the sedimentation length determined by the effective temperature of the free self-propelled particle. In the presence of a quadratic external potential the stationary state distribution has a Gaussian form. However, in general, this distribution is not determined by the effective temperature of the free self-propelled particle.
Cite
@article{arxiv.1404.0765,
title = {A self-propelled particle in an external potential: is there an effective temperature?},
author = {Grzegorz Szamel},
journal= {arXiv preprint arXiv:1404.0765},
year = {2014}
}
Comments
6 pages