Fluctuation theorems for a non-Gaussian system

TL;DR

This paper numerically verifies fluctuation theorems for a non-Gaussian Brownian system with heterogeneous thermal bath using the diffusing-diffusivity model, confirming their validity beyond Gaussian assumptions.

Contribution

It demonstrates the applicability of fluctuation theorems to non-Gaussian systems with heterogeneous environments using numerical methods.

Findings

Jarzynski equality and Crook fluctuation theorem hold for non-Gaussian systems.

Work distribution remains non-Gaussian even at large process times.

Heterogeneity in the thermal bath affects the work distribution shape.

Abstract

In this work, we numerically verify the Jarzynski equality and Crook fluctuation theorem for a Brownian particle diffusing in a heterogeneous thermal bath and hence having a non-Gaussian position distribution. We use the diffusing-diffusivity model to take the account of heterogeneity of the thermal bath where the mobility is considered as a fluctuating quantity. The Brownian particle is confined by a time-dependent harmonic potential. By changing the stiffness coefficient, we perform an isothermal process. We use the stochastic thermodynamics framework to calculate the work. We find that the Jarzynski equality and the Crook fluctuation theorem are convincingly satisfied for a non-Gaussion system. We also find that the work distribution is non-Gaussian for diffusing-diffusivity system even at a larger process time.