From Non-Thermal to Thermal: Cosmological Imprints of Self-Interacting Secluded Dark Matter
The study investigates how dark matter (DM) produced from an oscillating inflaton field thermalizes through self-interactions. Numerical solutions show that the DM temperature and chemical potential depend on inflaton mass and reheat temperature, leading to specific lower mass limits based on cosmological observations like BBN and CMB. Self-scattering primarily affects the free-streaming length, weakening the mass constraints by about 40% compared to non-thermal scenarios.