Subdominant Dark Matter sterile neutrino resonant production in the light of Planck

Understand

Few independent detections of a weak X-ray line at an energy of $\sim$3.5 keV seen toward a number of astrophysical sites have been reported.

• If this signal will be confirmed to be the signature of decaying DM sterile neutrino with a mass of ~7.1 keV, then the cosmological observables should be consistent with its properties.
• In this paper we make a coupled treatment of the weak decoupling, primordial nucleosynthesis and photon decoupling epochs in the sterile neutrino resonant production scenario, including the extra radiation energy density via N_eff.
• We compute the radiation and matter perturbations including the full resonance sweep solution for active-sterile flavor conversion in the expanding Universe.