Primordial Black Hole Neutrinogenesis of Sterile Neutrino Dark Matter

TL;DR

This paper explores a novel mechanism for producing sterile neutrino dark matter via primordial black hole evaporation, resulting in a distinct spectrum and potential observational signatures like X-ray and gravitational wave coincidences.

Contribution

It introduces a new production process for sterile neutrinos that does not rely on active-sterile mixing, expanding dark matter models and observational prospects.

Findings

Sterile neutrinos can be produced by black hole evaporation with a unique spectrum.

Produced sterile neutrinos could serve as warm dark matter in a broad mass range.

Potential observational signatures include coincident X-ray and gravitational wave signals.

Abstract

Sterile neutrinos are well-motivated and actively searched for new particles that would mix with the active neutrinos. We study their phenomenology when they are produced in the evaporation of early Universe black holes, a novel production mechanism that differs from all others and does not depend on the active-sterile mixing. The resulting hotter sterile neutrinos have a distinct spectrum and could be warm dark matter in the 0.3 MeV to 0.3 TeV mass range, distinct from the typical keV range. The possible coincidence of X-rays and gravitational waves is a unique novel signature of our scenario.