A selection of nonequilibrium issues

TL;DR

This paper provides a pedagogical overview of recent topics in nonequilibrium statistical mechanics, focusing on formal structures, symmetries, inequalities, and the role of entropy in linking microscopic dynamics to macroscopic irreversibility.

Contribution

It introduces formal frameworks for nonequilibrium systems, discusses symmetries and inequalities, and explores entropy's role in quantum and classical macroscopic states.

Findings

Explanation of fluctuation symmetry and Jarzynski equality

Construction of quantum macroscopic states

Result on the equivalence of ensembles

Abstract

We give a pedagogical introduction to a selection of recently discussed topics in nonequilibrium statistical mechanics, concentrating mostly on formal structures and on general principles. Part I contains an overview of the formalism of lattice gases that we use to explain various symmetries and inequalities generally valid for nonequilibrium systems, including the fluctuation symmetry, Jarzynski equality, and the direction of currents. In Part II we concentrate on the macroscopic state and how entropy provides a bridge between microscopic dynamics and macroscopic irreversibility; included is a construction of quantum macroscopic states and a result on the equivalence of ensembles.