Limits on light primordial black holes from high-scale leptogenesis
Roberta Calabrese, Marco Chianese, Jacob Gunn, Gennaro Miele, Stefano Morisi, Ninetta Saviano
Abstract
We investigate the role that the evaporation of light primordial black holes may have played in the production of the baryon asymmetry of the Universe through high-scale leptogenesis. In particular, for masses of primordial black holes in the range $[{10}^{6}--{10}^{9}]\text{ }\text{ }\mathrm{g}$, we find a dilution of thermally generated lepton asymmetry via entropy injection in the primordial plasma after the sphaleron freeze-out. As a consequence, we can put strong constraints on the primordial black hole parameters, showing the mutual exclusion limits between primordial black holes and high-scale leptogenesis. Remarkably, we point out an interplay between the upper bound on the initial abundance of primordial black holes and the active neutrino mass scale.