Mapping current fluctuations of stochastic pumps to nonequilibrium steady states

TL;DR

This paper demonstrates a refined mapping between current fluctuations in stochastic pumps and nonequilibrium steady states, allowing for a better understanding of fluctuation behavior and entropy production decomposition.

Contribution

It introduces an improved mapping that equates not only average currents but also their fluctuations, and decomposes entropy production in stochastic pumps.

Findings

Current fluctuations in stochastic pumps can be mapped to steady states.

The mapping ensures equivalence of fluctuations and averages.

A universal bound on current fluctuations is established.

Abstract

We show that current fluctuations in a stochastic pump can be robustly mapped to fluctuations in a corresponding time-independent nonequilibrium steady state. We thus refine a recently proposed mapping so that it ensures equivalence of not only the averages, but also optimal representation of fluctuations in currents and density. Our mapping leads to a natural decomposition of the entropy production in stochastic pumps similar to the "housekeeping" heat. As a consequence of the decomposition of entropy production, the current fluctuations in weakly perturbed stochastic pumps are shown to satisfy a universal bound determined by the steady state entropy production.