Gravitational Particle Production in Gravity Theories with Non-minimal Derivative Couplings

TL;DR

This paper investigates how non-minimal derivative couplings in gravity theories affect the gravitational production of heavy particles after inflation, finding that stronger couplings suppress particle production.

Contribution

It introduces the impact of derivative couplings to the Einstein tensor on gravitational particle production, a novel aspect in inflationary cosmology models.

Findings

Stronger derivative couplings suppress particle production.

Particle production is sensitive to the coupling strength.

Implications for dark matter and early universe cosmology.

Abstract

We study the gravitational production of heavy X-particles of mass of the order of the inflaton mass, produced after the end of inflation. We find that, in the presence of a derivative coupling of the inflaton field or of the X-field to the Einstein tensor, the number of gravitationally produced particles is suppressed as the strength of the coupling is increased.