Transition-path sampling for Run-and-Tumble particles

TL;DR

This paper extends transition-path sampling to active Run-and-Tumble particles, enabling the study of rare transition events despite their non-equilibrium nature, by defining suitable backward dynamics.

Contribution

It introduces a generalized transition-path sampling method for non-equilibrium active particles, overcoming reversibility constraints.

Findings

Successfully characterized transition pathways of Run-and-Tumble particles crossing barriers.

Demonstrated the method's validity for non-equilibrium active matter.

Provided insights into the kinetics of rare events in active particle systems.

Abstract

We elaborate and validate a generalization of the renowned transition-path-sampling algorithm for a paradigmatic model of active particles, namely the Run-and-Tumble particles. Notwithstanding the non-equilibrium character of these particles, we show how the consequent lack of the microscopical reversibility property, which is usually required by transition-path sampling, can be circumvented by identifying reasonable backward dynamics with a well-defined path-probability density. Our method is then applied to characterize the structure and kinetics of rare transition pathways undergone by Run-and-Tumble particles having to cross a potential barrier in order to find a target.