Non-Gaussianity after many-field reheating

TL;DR

This study numerically explores how reheating after quadratic inflation with many fields influences non-Gaussianity, revealing that specific initial conditions and parameters are necessary for detectable signals.

Contribution

It provides the first detailed numerical analysis of non-Gaussianity production in multi-field reheating scenarios with up to 65 fields.

Findings

Reheating significantly affects non-Gaussianity levels.

Detectable non-Gaussianity requires specific initial conditions and parameter ordering.

The impact may differ in the N-flation limit.

Abstract

We numerically investigate reheating after quadratic inflation with up to 65 fields, focusing on the production of non-Gaussianity. We consider several sets of initial conditions, masses and decay rates. As expected we find that the reheating phase can have a significant effect on the non-Gaussian signal, but that for this number of fields a detectable level of non-Gaussianity requires the initial conditions, mass range and decay rates to be ordered in a particular way. We speculate on whether this might change in the N-flation limit.