Non-canonical inflation coupled to matter

TL;DR

This paper investigates how conformally coupled non-relativistic matter can abruptly interrupt inflation in superconformal models, especially when initial matter density is significant, highlighting implications for higher-dimensional theories.

Contribution

It demonstrates that matter coupling can cause sudden inflation termination, providing a new perspective on inflation dynamics in superconformal and higher-dimensional frameworks.

Findings

Inflation can be abruptly stopped by matter coupling under certain conditions.

Corrections to the inflationary potential depend on initial matter density.

This effect is relevant for theories with extra dimensions like Kaluza-Klein modes.

Abstract

We compute corrections to the inflationary potential due to conformally coupled non-relativistic matter. We find that under certain conditions of the matter coupling, inflation may be interrupted abruptly. We display this in the superconformal Starobinsky model, where matter is conformally coupled to the Einstein frame metric. These corrections may easily stop inflation provided that there is an initial density of non-relativistic matter. Since these additional heavy degrees of freedom generically occur in higher dimension theories, for example as Kaluza-Klein modes, this effect can arise in multiple scenarios.