Mean-field 'Temperature' in Far From Equilibrium Systems

TL;DR

This paper defines a generalized 'temperature' for nonequilibrium systems, enabling the use of equilibrium concepts to describe systems under external forces or with nonequilibrium baths.

Contribution

It introduces a mean-field 'temperature' for nonequilibrium systems and proves a generalized fluctuation-dissipation relation applicable to such systems.

Findings

Generalized fluctuation-dissipation relation established

Mean-field 'temperature' applicable to systems with external forces

Modification of chemical equilibrium and Kramers rates by external forces

Abstract

We calculate the nonequilibrium mean-field 'temperature' of a Brownian system in contact with a heat bath. We consider two different cases: an equilibrium bath in the presence of strong external forces and a nonequilibrium bath. By proving the existence of a generalized fluctuation-dissipation relation this mean-field 'temperature' can be used to describe a nonequilibrium system as is if it were in thermal equilibrium with a thermal bath at the mean-field 'temperature' mentioned above. We apply our results to chemical reactions in the presence of external forces showing how chemical equilibrium and Kramers rate constants are modified by the presence of these forces.