Particle creation in the oscillatory phase of inflaton

TL;DR

This paper investigates particle creation during the inflaton's oscillatory phase in a flat universe using thermal squeezed states, revealing oscillatory particle production influenced by quantum and thermal effects.

Contribution

It introduces a thermal squeezed state formalism to analyze particle creation during inflaton oscillations, providing approximate solutions to the semiclassical Einstein equations.

Findings

Particle creation occurs during inflaton oscillations.

Created particles exhibit oscillatory behavior.

The solutions follow a power-law expansion similar to classical models.

Abstract

A thermal squeezed state representation of inflaton is constructed for a flat Friedmann-Robertson-Walker background metric and the phenomenon of particle creation is examined during the oscillatory phase of inflaton, in the semiclassical theory of gravity. An approximate solution to the semiclassical Einstein equation is obtained in thermal squeezed state formalism by perturbatively and is found obey the same power-law expansion as that of classical Einstein equation. In addition to that the solution shows oscillatory in nature except on a particular condition. It is also noted that, the coherently oscillating nonclassical inflaton, in thermal squeezed vacuum state, thermal squeezed state and thermal coherent state, suffer particle production and the created particles exhibit oscillatory behavior. The present study can account for the post inflation particle creation due to thermal and quantum effects of inflaton in a flat FRW universe.