Time Reversal Invariance of quantum kinetic equations: Nonequilibrium Green Functions Formalism

TL;DR

This paper demonstrates analytically that quantum kinetic equations derived from nonequilibrium Green functions and $\

Contribution

It establishes that quantum kinetic equations based on the Green functions formalism and $\

Findings

Quantum kinetic equations from Green functions are time reversal invariant.

$\\Phi$-derivable selfenergy approximations preserve time reversal symmetry.

The relation between statistical physics and time reversal symmetry is clarified.

Abstract

Time reversal symmetry is a fundamental property of many quantum mechanical systems. The relation between statistical physics and time reversal is subtle and not all statistical theories conserve this particular symmetry, most notably hydrodynamic equations and kinetic equations such as the Boltzmann equation. In this article it is shown analytically that quantum kinetic generalizations of the Boltzmann equation that are derived using the nonequilibrium Green functions formalism as well as all approximations that stem from $\Phi$-derivable selfenergies are time reversal invariant.