Towards a Theory of Entropy Production in the Little and Big Bang

TL;DR

This paper introduces a new formalism based on the Husimi transform to describe entropy production in quantum processes, linking it to classical chaos measures, with applications in cosmology and heavy ion collisions.

Contribution

It presents a novel approach to quantify quantum entropy production using Husimi functions, connecting quantum and classical entropy growth rates.

Findings

Weber entropy growth approaches Kolmogorov-Sinai entropy in tractable cases.

Formalism applies to early universe reheating and heavy ion collisions.

Provides a framework for entropy production in quantum systems.

Abstract

We propose a broadly applicable formalism for the description of coarse grained entropy production in quantum mechanical processes. Our formalism is based on the Husimi transform of the quantum state, which encodes the notion that information about any quantum state is limited by the experimental resolution. We show in two analytically tractable cases (the decay of an unstable vacuum state and reheating after cosmic inflation) that the growth rate of the Wehrl entropy associated with the Husimi function approaches the classical Kolmogorov-Sinai entropy. We also discuss various possible applications of our formalism, including the production of entropy in the early stages of a relativistic heavy ion collision.