Addressing the Hubble tension with Sterile Neutrino Dark Matter

Abstract

One of the promising dark matter (DM) candidates is a keV-scale sterile neutrino. In the early universe, the observed relic of the sterile neutrino DM is generated via the Dodelson-Widrow mechanism. However, this production scenario is severely constrained by various astrophysical observations. Many non-standard interactions between active (${\nu }_a$) and sterile (${\nu }_s$) neutrinos have been proposed to evade these astrophysical bounds. Here, we study sterile neutrinos in the context of a mass-varying scenario by coupling both active and sterile neutrinos to a scalar field. This novel mechanism opens up a new parameter space that generates the observed DM relic and addresses the Hubble tension. We find that the resulting parameter space can be fully probed by future X-ray missions.

Comments: 8 pages, 5 captioned figures, accepted for publication in Physical Review D as a Letter