Gravitational Radiation from Preheating with Many Fields

TL;DR

This paper investigates how the presence of multiple fields coupled to the inflaton affects preheating and gravitational wave production after inflation, demonstrating that these processes are robust even with many matter fields involved.

Contribution

It introduces simulations of preheating with multiple coupled fields, extending previous single-field models to more realistic multi-field scenarios.

Findings

Preheating remains effective with many coupled fields.

Gravitational wave signatures are robust to multiple matter couplings.

Simulations confirm the stability of preheating dynamics in complex models.

Abstract

Parametric resonances provide a mechanism by which particles can be created just after inflation. Thus far, attention has focused on a single or many inflaton fields coupled to a single scalar field. However, generically we expect the inflaton to couple to many other relativistic degrees of freedom present in the early universe. Using simulations in an expanding Friedmann-Lema\^itre-Robertson-Walker spacetime, in this paper we show how preheating is affected by the addition of multiple fields coupled to the inflaton. We focus our attention on gravitational wave production--an important potential observational signature of the preheating stage. We find that preheating and its gravitational wave signature is robust to the coupling of the inflaton to more matter fields.