Gravitational-Wave Mediated Preheating

TL;DR

This paper introduces a novel preheating mechanism where gravitational waves, amplified by an inflation-graviton coupling, transfer energy from the inflaton to matter fields without direct couplings, offering a new perspective on early universe dynamics.

Contribution

It presents a new preheating process mediated by gravitational waves coupled to the inflaton and matter fields, avoiding direct inflaton-matter interactions.

Findings

Gravitational waves are exponentially enhanced via inflation-graviton coupling.

Energy transfer from inflaton to matter occurs through gravitational wave interactions.

Preheating can occur rapidly during matter domination under certain energy scale constraints.

Abstract

We propose a new preheating mechanism through the coupling of the gravitational field to both the inflaton and matter fields, without direct inflaton-matter couplings. The inflaton transfers power to the matter fields through interactions with gravitational waves, which are exponentially enhanced due to an inflation-graviton coupling. One such coupling is the product of the inflaton to the Pontryagin density, as in dynamical Chern-Simons gravity. The energy scales involved are constrained by requiring that preheating happens fast during matter domination.