Reheating in two-sector cosmology

Understand

We analyze reheating scenarios where a hidden sector is populated during reheating along with the sector containing the Standard Model.

• We numerically solve the Boltzmann equations describing perturbative reheating of the two sectors, including the full dependence on quantum statistics, and study how quantum statistical effects during reheating as well as the non-equilibrium inflaton-mediated energy transfer between the two sectors affects the temperature evolution of the two radiation baths.
• We obtain new power laws describing the temperature evolution of fermions and bosons when quantum statistics are important during reheating.
• We show that inflaton-mediated scattering is generically most important at radiation temperatures $T\sim M_\phi/4$, and build on this observation to obtain analytic estimates for the temperature asymmetry produced by asymmetric reheating.