Speaker
Description
Heavy, unstable, and out-of-equilibrium particles with a matter equation of state appear in many well-motivated cosmological histories; examples include the inflaton condensate and moduli fields. Decays of the matter component result in highly relativistic non-thermal SM particles that must subsequently attain thermal equilibrium. We focus on cascades of $2 \to 3$ gauge interactions of the SM as the primary means of thermalization at high energies. Paying particular attention to coherent plasma effects and the role of the decaying particle's mass and branching ratios, we study the energy-spectra of SM particles emerging from the thermalization cascade. Finally, we comment on potential applications of such energetic non-thermal particles in cosmology and, in particular, heavy DM production.
