Inflaton freeze-out

TL;DR

This paper explores a scenario where the inflaton reaches thermal equilibrium after inflation and freezes out, affecting dark matter relic density and potentially leading to observable Higgs decays at the LHC.

Contribution

It introduces a model where inflaton freeze-out influences dark matter abundance and predicts possible invisible Higgs decays into inflaton pairs.

Findings

Inflaton freeze-out can produce the correct dark matter relic density.

The model allows for significant Higgs-inflaton coupling.

Potential for invisible Higgs decay signatures at the LHC.

Abstract

We study the possibility that, after inflation, the inflaton reaches thermal equilibrium with the Standard Model thermal bath and eventually freezes-out in the non-relativistic regime. When the inflaton decay is the sole source of (non-thermal) dark matter, its relic density is automatically suppressed. We delineate parameter space leading to the correct dark matter abundance. The model allows for a significant Higgs-inflaton coupling which may lead to invisible Higgs decay into inflaton pairs at the LHC.