Fluctuation relations and rare realizations of transport observables

TL;DR

This paper investigates the role of rare fluctuations in transport observables under nonequilibrium conditions, using a stochastic path integral approach to analyze fluctuation relations and their limitations.

Contribution

It introduces a stochastic path integral framework to quantify rare transport fluctuations and demonstrates their impact on fluctuation relations in nonequilibrium systems.

Findings

Rare realizations cause massive fluctuations that can obscure fluctuation identities.

Quantitative estimates of fluctuations are provided for a mesoscopic RC circuit.

Rare events significantly influence the statistical behavior of transport observables.

Abstract

Fluctuation relations establish rigorous identities for the nonequilibrium averages of observables. Starting from a general transport master equation with time-dependent rates, we employ the stochastic path integral approach to study statistical fluctuations around such averages. We show how under nonequilibrium conditions, rare realizations of transport observables are crucial and imply massive fluctuations that may completely mask such identities. Quantitative estimates for these fluctuations are provided. We illustrate our results on the paradigmatic example of a mesoscopic RC circuit.