WIMPflation

TL;DR

This paper introduces models where the inflaton, produced as a thermal relic, acts as dark matter, with reheating and inflationary predictions compatible with observations, and explores detection prospects.

Contribution

It presents a novel class of inflationary models where the inflaton is also dark matter, including specific potentials and Higgs portal interactions.

Findings

Inflaton can be a thermal relic dark matter candidate.

Models can match cosmic microwave background observations.

Higgs portal interactions offer prospects for direct detection.

Abstract

We propose a class of models in which a stable inflaton is produced as a thermal relic in the early universe and constitutes the dark matter. We show that inflaton annihilations can efficiently reheat the universe, and identify several examples of inflationary potentials that can accommodate all cosmic microwave background observables and in which the inflaton dark matter candidate has a weak scale mass. As a simple example, we consider annihilations that take place through a Higgs portal interaction, leading to encouraging prospects for future direct detection experiments.