Thermal effects in neutrino dark matter production

The origin of the dark matter of the Universe and the mechanism generating light neutrino masses could be tightly linked. In this talk, based on arXiv:2308.01341, we consider the possibility to simultaneously explain oscillation data and dark matter in the form of a keV-sterile neutrino. We thoroughly study the DM production through freeze-in two-body decays, accounting for thermal effects modifying the neutrino mixing and thus the production rates. Our study shows that the freeze-in dark matter production can be efficient and thus further study is necessary to identify interesting regions of parameter space that simultaneously account for DM and neutrino masses.