Thermal blocking of preheating

TL;DR

This paper investigates how thermal effects can halt or delay preheating after inflation, using numerical simulations to assess the accuracy of effective mass approximations in specific curvaton models.

Contribution

It provides a numerical analysis of thermal blocking in preheating, confirming the effectiveness of perturbative thermal mass estimates in predicting the end of preheating.

Findings

Thermal blocking can occur before preheating begins in some models.

Effective mass approximation accurately predicts the qualitative behavior.

Preheating end can be reliably estimated using this approach.

Abstract

The parametric resonance responsible for preheating after inflation will end when self-interactions of the resonating field and interactions of this field with secondary degrees of freedom become important. In many cases, the effect may be quantified in terms of an effective mass and the resulting shifting out of the spectrum of the strongest resonance band. In certain curvaton models, such thermal blocking can even occur before preheating has begun, delaying or even preventing the decay of the curvaton. We investigate numerically to what extent this thermal blocking is realised in a specific scenario, and whether the effective mass is well approximated by the perturbative leading order thermal mass. We find that the qualitative behaviour is well reproduced in this approximation, and that the end of preheating can be confidently estimated.