Fluctuation-dissipation relations outside the linear response regime in a two-dimensional driven lattice gas along the direction transverse to the driving force

TL;DR

This study numerically investigates a two-dimensional driven lattice gas, demonstrating the validity of fundamental fluctuation-dissipation relations outside the linear response regime in a nonequilibrium setting.

Contribution

It provides the first numerical evidence that Einstein, Green-Kubo, and fluctuation-response relations hold far from equilibrium in a driven lattice gas model.

Findings

Einstein relation remains valid outside linear response.

Green-Kubo relation holds far from equilibrium.

Fluctuation-response relation is confirmed in nonequilibrium conditions.

Abstract

We performed numerical experiments on a two-dimensional driven lattice gas, which constitutes a simple stochastic nonequilibrium many-body model. In this model, focusing on the behavior along the direction transverse to the external driving force, we numerically measure transport coefficients and dynamical fluctuations outside the linear response regime far from equilibrium. Using these quantities, we find the validity of the Einstein relation, the Green-Kubo relation and the fluctuation-response relation.