Might the Dark Matter also be the Inflaton?

Dark matter and inflation represent two of the biggest open question in cosmology. Although they are generally thought of as distinct and unrelated phenomena, here I will ask whether they might be closely connected. In particular, I will describe a class of models in which a stable inflaton is produced as a thermal relic in the early universe and constitutes the dark matter. I will show that the annihilations of these inflatons can efficiently reheat the universe, and I will identify several examples of inflationary potentials within this scenario which can accommodate all cosmic microwave background observables. As a simple example, I will discuss a model in which inflaton annihilations that take place through a Higgs portal interaction, leading to encouraging prospects for future direct detection experiments.