A large deviation principle for the multispecies stirring process

TL;DR

This paper establishes a large deviation principle for the multispecies stirring process on a discrete torus, extending existing methods to a multi-species context and analyzing the hydrodynamic limit and mobility matrix.

Contribution

It introduces a novel large deviation principle for multispecies stirring processes and adapts the superexponential estimate method to this setting.

Findings

Proves a large deviation principle for multispecies densities.

Derives the hydrodynamic limit for the process.

Identifies the mobility matrix with the covariance of the multinomial distribution.

Abstract

In this paper we consider the multispecies stirring process on the discrete torus. We prove a large deviation principle for the trajectory of the vector of densities of the different species. The technique of proof consists in extending the method of the foundational paper [1] based on the superexponential estimate to the multispecies setting. This requires a careful choice of the corresponding weakly asymmetric dynamics, which is parametrized by fields depending on the various species. We also prove the hydrodynamic limit of this weakly asymmetric dynamics, which is similar to but different from the ABC model in [2]. Using the appropriate asymmetric dynamics, we also obtain that the mobility matrix relating the drift currents to the fields coincides with the covariance matrix of the reversible multinomial distribution, which then further leads to the Einstein relation