Freeze-in Dark Matter: Problems and Opportunities

Abstract

FIMP dark matter is produced via the freeze-in mechanism, which implies tiny couplings between the DM and the standard model particles. We will discuss the motivation behind FIMP dark matter and will study simple models of FIMPs. We will compare them with standard thermal freeze-out production, analyse the model predictions and possible observable signatures. In the second part of the lecture, we will consider the assumptions behind the freeze-in production mechanism and its shortcomings. Finally, we will discuss new avenues and connections to others beyond the standard model open problems.