Non equilibrium mode coupling theory for supercooled liquids and glasses

TL;DR

This paper develops a non-equilibrium mode coupling theory that extends the classical framework to describe the dynamics of supercooled liquids and glasses far from equilibrium, using a formalism based on memory functions and collective frequencies.

Contribution

It introduces a formally exact set of equations for non-equilibrium classical liquids and glasses, generalized through mode coupling approximations to handle far-from-equilibrium conditions.

Findings

Derivation of exact equations for non-equilibrium correlation functions.

Extension of mode coupling theory to non-equilibrium states.

Framework applicable to supercooled liquids and glasses far from equilibrium.

Abstract

A formally exact set of equations is derived for the description of nonequilibrium phenomena in classical liquids and glasses. With the help of a non equilibrium projection operator formalism, the correlation functions and fluctuation propagators are expressed in terms of memory functions and time dependent collective frequencies. This formally exact set of equations is approximated by applying mode coupling approximations to the memory functions. The resulting set of equations for wavevector dependent correlation functions, fluctuation propagators and one-time structure factors $S_q(t)$ generalizes the well known mode coupling theory of the glass transition to situations far away from equilibrium.