Sterile neutrino dark matter catalyzed by a very light dark photon

Sterile neutrinos (vs) that mix with active neutrinos (va) are interesting dark mat-ter candidates with a rich cosmological and astrophysical phenomenology. In their simplest incarnation, their production is severely constrained by a combination of structure formation observations and X-ray searches. We show that if active neutrinos couple to an oscillating condensate of a very light Li,- LT gauge field, resonant va-vs oscillations can occur in the early universe, consistent with vs constituting all of the dark matter, while respecting X-ray constraints on vs + va-y decays. Interesting deviations from standard solar and atmospheric neutrino oscillations can persist to the present.

Automated summary

Sterile neutrinos that mix with active neutrinos are considered as interesting dark matter candidates, with their production being constrained by structure formation observations and X-ray searches. Resonant oscillations between active and sterile neutrinos can occur in the early universe if active neutrinos couple to an oscillating condensate of a very light gauge field, allowing sterile neutrinos to potentially make up all of the dark matter while respecting X-ray constraints. These deviations from standard neutrino oscillations could still be present today.