We show that the reheating temperature of a matter-domination era in the early universe can be pushed down to the neutrino decoupling temperature at around $2 \ { \rm MeV}$ if the reheating takes place through non-hadronic decays of the dominant matter and neutrino-antineutrino asymmetries are still large enough, $|L| \gtrsim \mathcal{ O}(10^{ -2})$ (depending on the neutrino flavor) at the end of reheating.
Categories: astro-ph.CO