Non equilibrium statistical physics with fictitious time

TL;DR

This paper proposes using a fictitious time dimension, inspired by stochastic quantization, to address non-equilibrium statistical physics problems, restoring a fluctuation dissipation theorem and offering a new analytical perspective.

Contribution

It introduces a novel approach replacing response fields with a fictitious time dimension, providing a new framework for non-equilibrium statistical physics analysis.

Findings

Fictitious time restores fluctuation dissipation theorem.

Provides a new analytical outlook for non-equilibrium problems.

Connects stochastic quantization with non-equilibrium physics.

Abstract

Problems in non equilibrium statistical physics are characterized by the absence of a fluctuation dissipation theorem. The usual analytic route for treating these vast class of problems is to use response fields in addition to the real fields that are pertinent to a given problem. This line of argument was introduced by Martin, Siggia and Rose. We show that instead of using the response field, one can, following the stochastic quantization of Parisi and Wu, introduce a fictitious time. In this extra dimension a fluctuation dissipation theorem is built in and provides a different outlook to problems in non equilibrium statistical physics.