Fluctuation theorem for stochastic dynamics

TL;DR

This paper discusses a fluctuation theorem applicable to stochastic Langevin dynamics, leading to a nonlinear fluctuation-dissipation relation for equilibrium systems under strong perturbations.

Contribution

It extends the fluctuation theorem to finite systems with Langevin dynamics and derives a nonlinear fluctuation-dissipation theorem for strongly perturbed equilibrium systems.

Findings

Fluctuation theorem holds for finite Langevin systems.

Derivation of a nonlinear fluctuation-dissipation relation.

Applicable to systems under arbitrarily strong fields.

Abstract

The fluctuation theorem of Gallavotti and Cohen holds for finite systems undergoing Langevin dynamics. In such a context all non-trivial ergodic theory issues are by-passed, and the theorem takes a particularly simple form. As a particular case, we obtain a nonlinear fluctuation-dissipation theorem valid for equilibrium systems perturbed by arbitrarily strong fields.