Inhomogeneous asymmetric exclusion processes between two reservoirs : large deviations for the local empirical observables in the Mean-Field approximation

TL;DR

This paper develops a Mean-Field approximation framework to analyze large deviations of local empirical observables in inhomogeneous exclusion processes between reservoirs, providing explicit results for TASEP and ASEP models.

Contribution

It introduces a Mean-Field approximation for empirical densities and activities, enabling explicit large deviation rate functions for inhomogeneous exclusion processes.

Findings

Large deviations for empirical density and current in TASEP and ASEP models.

Explicit contraction formulas for density profile large deviations.

Discussion of implications for space-local time-additive observables.

Abstract

For a given inhomogeneous exclusion processes on $N$ sites between two reservoirs, the trajectories probabilities allow to identify the relevant local empirical observables and to obtain the corresponding rate function at Level 2.5. In order to close the hierarchy of the empirical dynamics that appear in the stationarity constraints, we consider the simplest approximation, namely the Mean-Field approximation for the empirical density of two consecutive sites, in direct correspondence with the previously studied Mean-Field approximation for the steady state. For a given inhomogeneous Totally Asymmetric model (TASEP), this Mean-Field approximation yields the large deviations for the joint distribution of the empirical density profile and of the empirical current around the mean-field steady state; the further explicit contraction over the current allows to obtain the large deviations of the empirical density profile alone. For a given inhomogeneous Asymmetric model (ASEP), the local empirical observables also involve the empirical activities of the links and of the reservoirs; the further explicit contraction over these activities yields the large deviations for the joint distribution of the empirical density profile and of the empirical current. The consequences for the large deviations properties of time-additive space-local observables are also discussed in both cases.