2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/131657We describe an extention of the Standard Model (the $ν$MSM) by three light singlet Majorana fermions -- sterile neutrinos, which allows to address simultaneously the problem of neutrino oscillations and the problems of dark matter and baryon asymmetry of the Universe. We discuss the ways these new particles can be searched for in astrophysical, laboratory, and accelerator experiments.16 pages, Talk given at 12th International Workshop on Neutrinos Telescopes: Twenty Years after the Supernova 1987A Neutrino Bursts Discovery, Venice, Italy, 6-9 Mar 2007High Energy Physics - Phenomenologytext