Tight bonds between sterile neutrinos and dark matter

Understand

Despite the astonishing success of standard $\Lambda$CDM cosmology, there is mounting evidence for a tension with observations at small and intermediate scales.

• We introduce a simple model where both cold dark matter (DM) and sterile neutrinos are charged under a new $U(1)_X$ gauge interaction.
• The resulting DM self-interactions resolve the tension with the observed abundances and internal density structures of dwarf galaxies.
• At the ame time, the sterile neutrinos can account for both the small hot DM component favored by cosmological observations and the neutrino anomalies found in short-baseline experiments.