Description
Sterile neutrinos are compelling dark matter (DM) candidates, yet the minimal Dodelson-Widrow production mechanism solely based on active sterile oscillations is excluded by astrophysical observations. Non-standard self-interactions in either the active or sterile sector are known to alter the sterile neutrino DM production in the early universe, which could alleviate the tension with astrophysical constraints to some extent. Here we propose a novel solution where scalar-mediated non-standard interactions between active and sterile neutrinos generate new production channels for sterile neutrino DM, independent of the active-sterile mixing and without the need for any fine-tuned resonance or primordial lepton asymmetry. We discuss two cases. This framework enables efficient sterile neutrino DM production even at vanishingly small mixing angles and opens up new viable regions of parameter space that can be tested with future X-ray and gamma-ray observations. We will consider the case of both heavy and light mediators. Some of the constraints coming from astrophysics and cosmology will also be discussed.