Dark Matter from Exponential Growth

Abstract

We propose a novel mechanism for the production of dark matter (DM) from a thermal bath based on the idea that DM particles $χ$ can transform heat bath particles $ψ: χψ→χχ$. For a small initial abundance of $χ$, this leads to an exponential growth of the DM number density in close analogy to other familiar exponential growth processes in nature. We demonstrate that this mechanism complements freeze-in and freeze-out production in a generic way, opening new parameter space to explain the observed DM abundance, and we discuss observational prospects for such scenarios.

Topics & Concepts