2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/109903The observed baryon asymmetry of the Universe is suitably created in thermal leptogenesis through the out-of-equilibrium decay of $N_1$, the lightest of the three heavy singlet neutral fermions which anchor the seesaw mechanism to obtain small Majorana neutrino masses. However, this scenario suffers from the incompatibility of a generic lower bound on the mass of $N_1$ and the upper bound on the reheating temperature of the Universe after inflation. A modest resolution of this conundrum is proposed.7 pages, 1 figureHigh Energy Physics - Phenomenologytext