Lepton Flavour Asymmetries and the Mass Spectrum of Primordial Black Holes

Abstract

We study the influence of lepton flavour asymmetries on the formation and the mass spectrum of primordial black holes. We estimate the detectability of their mergers with LIGO/Virgo and show that the currently published gravitational wave events may actually be described by a primordial black hole spectrum from non-zero asymmetries. We suggest to use gravitational-wave astronomy as a novel tool to probe how lepton flavour asymmetric the Universe has been before the onset of neutrino oscillations.

Comments: v3: Minor improvements to match published version; includes ancillary files with data of the figures