Slow-Roll Inflation in the Presence of a Dark Energy Coupling

TL;DR

This paper investigates how a coupling between dark energy and the inflaton affects slow-roll inflation, the dynamics of the scalar fields, and the resulting primordial perturbations, with implications for reheating processes.

Contribution

It introduces a model where dark energy coupling influences inflation dynamics, showing the scalar field's attraction to the potential minimum and effects on expansion and perturbations.

Findings

Coupling causes the quintessence field to be attracted to the potential minimum.

Large coupling makes the quintessence field heavy and at the minimum.

The coupling impacts the inflationary expansion rate and reheating processes.

Abstract

In models of coupled dark energy, in which a dark energy scalar field couples to other matter components, it is natural to expect a coupling to the inflaton as well. We explore the consequences of such a coupling in the context of single field slow-roll inflation. Assuming an exponential potential for the quintessence field we show that the coupling to the inflaton causes the quintessence field to be attracted towards the minimum of the effective potential. If the coupling is large enough, the field is heavy and is located at the minimum. We show how this affects the expansion rate and the slow-roll of the inflaton field, and therefore the primordial perturbations generated during inflation. We further show that the coupling has an important impact on the processes of reheating and preheating.