Classical-Quantum Correspondence for Fields

TL;DR

This paper introduces a classical-quantum correspondence (CQC) that maps quantum free bosonic fields in dynamic backgrounds to classical oscillators, enabling easier analysis of quantum radiation and backreaction effects.

Contribution

It presents a novel CQC method that transforms quantum field problems into classical systems, facilitating the study of quantum effects in classical backgrounds.

Findings

CQC allows calculation of quantum radiation in classical backgrounds.

The method can fully incorporate quantum backreaction effects.

Applicable to phenomena like quantum evaporation of oscillons.

Abstract

We map the quantum problem of a free bosonic field in a space-time dependent background into a classical problem. $N$ degrees of freedom of a real field in the quantum theory are mapped into $2N^2$ classical simple harmonic oscillators with specific initial conditions. We discuss how this classical-quantum correspondence (CQC) may be used to evaluate quantum radiation and fully treat the backreaction of quantum fields on classical backgrounds. The technique has widespread application, including to the quantum evaporation of classical breathers ("oscillons").