Particle production and reheating in the inflationary universe

TL;DR

This paper applies thermal field theory to inflationary models, revealing new insights into particle production, decay processes, and thermalisation during the early universe's inflationary phase.

Contribution

It introduces a novel analysis of particle production and decay in inflationary models using thermal field theory, including numerical solutions of the Boltzmann equation in an expanding universe.

Findings

Massive fields facilitate two-stage decay of light fields.

Particle distributions can thermalise during small amplitude inflaton oscillations.

New results for catalysed particle production in inflationary scenarios.

Abstract

Thermal field theory is applied to particle production rates in inflationary models, leading to new results for catalysed, or two-stage decay, where massive fields act as decay channels for the production of light fields. A numerical investigation of the Bolztmann equation in an expanding universe shows that the particle distributions produced during small amplitude inflaton oscillations or alongside slowly moving inflaton fields can thermalise.