Classical Preheating and Decoherence

TL;DR

This paper shows that the quantum evolution during cosmic preheating can be simulated classically with random initial conditions, and that parametric resonance causes both preheating and quantum decoherence.

Contribution

It establishes the equivalence between quantum and classical descriptions of preheating, enabling efficient simulations and linking parametric resonance to decoherence.

Findings

Classical simulation of quantum preheating is feasible.

Parametric resonance drives both preheating and decoherence.

Quantum decoherence occurs simultaneously with preheating.

Abstract

We establish the equivalence between the quantum evolution of spatially homogeneous oscillations of a scalar field and that of an analogous classical system with certain random initial condition. We argue that this observation can be used for numerical simulation of the Universe in the preheating epoch. We also explicitly demonstrate that the phenomenon of parametric resonance that leads to preheating is simultaneously an effective mechanism for generating quantum decoherence of the Universe.