Boosting the production of sterile neutrino dark matter with self-interactions

Understand

Sterile neutrinos are well-motivated and simple dark matter (DM) candidates.

• However, sterile neutrino DM produced through oscillations by the Dodelson-Widrow mechanism is excluded by current $X$-ray observations and bounds from structure formation.
• One minimal extension, that preserves the attractive features of this scenario, is self-interactions among sterile neutrinos.
• In this work, we analyze how sterile neutrino self-interactions mediated by a scalar affect the production of keV sterile neutrinos for a wide range of mediator masses.