Lepton number asymmetries and the lower bound on the reheating temperature

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 MeV if the reheating takes place through non-hadronic decays of the dominant matter and neutrino-antineutrino asymmetries are still large enough, |L| O(10⁻²) (depending on the neutrino flavor) at the end of reheating.