Harmonic Systems With Bulk Noises

TL;DR

This paper compares harmonic chains with bulk noises, analyzing their hydrodynamics, fluctuations, and correlations, revealing differences in their measures despite similar covariances in nonequilibrium states.

Contribution

It provides a detailed comparison of velocity flip and self-consistent reservoir bulk noises, extending some results to higher dimensions.

Findings

Different measures despite same covariances in NESS

Analysis of hydrodynamical scaling and large deviations

Long-range correlations identified

Abstract

We consider a harmonic chain in contact with thermal reservoirs at different temperatures and subject to bulk noises of different types: velocity flips or self-consistent reservoirs. While both systems have the same covariances in the nonequilibrium stationary state (NESS) the measures are very different. We study hydrodynamical scaling, large deviations, fluctuations, and long range correlations in both systems. Some of our results extend to higher dimensions.