Leptogenesis, dark matter and neutrino masses
  We review the viability of the sterile neutrino hypothesis in accounting for
three observational problems of the Standard Model of particle physics:
neutrino masses and lepton mixing, dark matter and the baryon asymmetry of the
Universe. We present two alternative scenarios for the implementation of the
sterile fermion hypothesis: the $\nu$MSM and the Inverse Seesaw.
