Fluctuation-Dissipation theorems and entropy production in relaxational systems

TL;DR

This paper establishes a bound linking the violation of fluctuation-dissipation relations to entropy production in out-of-equilibrium stochastic systems, applicable to diverse physical systems including glasses and aging materials.

Contribution

It extends fluctuation-dissipation theorems to far-from-equilibrium systems by relating their violations to entropy production, broadening their applicability beyond near-equilibrium conditions.

Findings

Violation of FDT is bounded by entropy production.

Applicable to diffusion, glasses, and macroscopic systems.

Bounds age-frequency regimes in aging systems.

Abstract

We show that for stochastic dynamical systems out of equilibrium the violation of the fluctuation-dissipation equality is bounded by a function of the entropy production. The result applies to a much wider situation than `near equilibrium', comprising diffusion as well as glasses and other macroscopic systems far from equilibrium. For aging systems this bounds the age-frequency regimes in which the susceptibilities satisfy FDT in terms of the rate of decay of the H-function, a question intimately related to the reading of a thermometer placed in contact with the system.