Leptogenesis from tiny violation of Lepton Number

The so-called ARS leptogenesis ensures a viable generation of the baryon asymmetry of the Universe by extending the Standard Model with GeV scale right-handed/sterile neutrinos which are being searched at present and next future experimental facilities. This kind of scenario is realized, in a technically natural way, in models, like the Linear and the Inverse see-saw, characterized by a tiny violation of the lepton number.