Speaker
Description
Sterile neutrinos are well-motivated and actively searched for hypothetical neutral particles that would mix with the Standard Model active neutrinos. They are considered prime warm dark matter (DM) candidates, typically when their mass is in the keV range, although they can also be hot or cold DM components.
We discuss in detail the characteristics and phenomenology of sterile neutrinos that minimally couple only to active neutrinos and are produced in the evaporation of early Universe primordial black holes (PBHs), a process we called ``PBH sterile neutrinogenesis". Contrary to the previously studied sterile neutrino production mechanisms, this novel mechanism does not depend on the active-sterile mixing. The resulting sterile neutrinos have a distinctive spectrum and are produced with larger energies than in typical scenarios. When PBHs matter- dominate before evaporating, the possible coincidence of induced gravitational waves associated with PBH evaporation and astrophysical X- ray observations from sterile neutrinos decays constitutes a distinct signature of our scenario.
In addition, we discuss the possibility of two distinct sterile neutrino populations making up the whole DM energy density in the regions where generating the whole DM density with only one production mechanism is restricted by the X-ray limit.
