New Frontiers in Sterile Neutrino Dark Matter: Constraining Non-Standard Neutrino Interaction Production using Astrophysical, Experimental, and X-ray Data

Sterile neutrinos remain a leading candidate for dark matter, with many experiments and observations testing their candidacy. Oscillation production from the Dodelson-Widrow and Shi-Fuller mechanisms are excluded and highly-constrained, respectively. We explore non-standard interactions (NSI) among active neutrinos arising from new mediators, including a dark scalar or vector boson, which open novel production mechanisms for sterile neutrinos to be the dark matter. Using constraints from thermal warm dark matter (WDM), we find that mediating dark scalars with a mass above 2.5 GeV are ruled out at 95% confidence, while each vector boson model can be partially constrained across its parameter space. We find novel results for the cases of NSI production methods that are explorable by large-scale structure, neutrino experiments, and X-ray astronomy.