Graviton- and Inflaton-mediated Dark Matter Production after Large Field Polynomial Inflation

TL;DR

This paper explores how large-field polynomial inflation models can produce dark matter through inflaton and graviton-mediated processes, revealing the significance of graviton channels in determining dark matter abundance.

Contribution

It introduces the role of graviton-mediated processes in dark matter production within large-field polynomial inflation, contrasting with small-field models.

Findings

Graviton-mediated processes can dominate dark matter production in large-field inflation.

The interplay between inflaton and graviton channels constrains dark matter mass and reheating temperature.

Non-trivial relations between dark matter properties and inflation parameters are established.

Abstract

Polynomial inflation is a simple cosmological scenario, which fits the cosmic microwave background data well. It provides testable predictions for the tensor-to-scalar ratio and the running of the spectral index. In this work, we investigate the production of Dirac dark matter (DM) within the framework of large-field polynomial inflation. We study all relevant production channels including $i$) non-thermal production through inflaton decays and scatterings, and $ii$) thermal production from scattering of standard model particles mediated by inflatons and gravitons. In contrast to small-field polynomial inflation, where inflaton decay dominates DM production, we find that graviton-mediated processes can be dominant in the large-field scenario. For DM lighter than the inflaton, we demonstrate that the interplay between graviton- and inflaton-mediated production channels give rise to non-trivial relations between the DM mass and the reheating temperature required to account for the DM relic abundance.