International audiencePrevious fits of sterile neutrino dark matter models to cosmological dataassumed a peculiar production mechanism, which is not representative of thebest-motivated particle physics models given current data on neutrinooscillations. These analyses ruled out sterile neutrino masses smaller than8-10 keV. Here we focus on sterile neutrinos produced resonantly. We show thattheir cosmological signature can be approximated by that of mixed Cold plusWarm Dark Matter (CWDM). We use recent results on LambdaCWDM models to showthat for each mass greater than or equal to 2 keV, there exists at least onemodel of sterile neutrino accounting for the totality of dark matter, andconsistent with Lyman-alpha and other cosmological data. Resonant productionoccurs in the framework of the nuMSM (the extension of the Standard Model withthree right-handed neutrinos). The models we checked to be allowed correspondto parameter values consistent with neutrino oscillation data, baryogenesis andall other dark matter bounds
