Dark Matter Production Mechanisms with a Non-Thermal Cosmological History - A Classification

Understand

We perform a comprehensive study of models of dark matter (DM) in a Universe with a non-thermal cosmological history, i.e with a phase of pressure-less matter domination before the onset of big-bang nucleosynethesis (BBN).

• Such cosmological histories are generically predicted by UV completions that contain gravitationally coupled scalar fields (moduli).
• We classify the different production mechanisms for DM in this framework, generalizing previous works by considering a wide range of DM masses/couplings and allowing for DM to be in equilibrium with a "dark" sector.
• We identify four distinct parametric regimes for the production of relic DM, and derive accurate semi-analytic approximations for the DM relic abundance.