Preheating and Reheating in Inflationary Cosmology: a pedagogical survey

TL;DR

This paper reviews recent advances in understanding preheating after inflation, emphasizing the importance of self-consistent, non-linear calculations and symmetry restoration phenomena in cosmological models.

Contribution

It provides a comprehensive pedagogical overview of preheating mechanisms, including analytical estimates, large N methods, and symmetry considerations in inflationary cosmology.

Findings

Preheating time scales can be estimated using Mathieu and Lamé approximations.

Self-consistent, energy-conserving calculations are crucial for accurate modeling.

Symmetry restoration during preheating depends on specific conditions and is analyzed in various theories.

Abstract

Recent progress in the preheating phenomena for inflationary cosmology is reviewed. We first discuss estimates of the preheating time scale and particle production at the early stages of parametric amplification within the Mathieu and Lam'e approximations and we analyze their precision and limitations. The necessity of self-consistent calculations including the non-linearity of the field theory equations in an energy conserving scheme is stressed. The large N calculations including the field back-reaction are reviewed. For spontaneously broken theories the issue of symmetry restoration is analyzed. A discussion of the possibility and criterion for symmetry restoration is presented.