ИСТИНА

The Standard Model of particle physics is currently unable to explain several observed phenomena, including: 1. neutrino oscillations detected in numerous experiments, which demonstrate the existence of neutrino masses and mixing between three neutrino generations; 2. the presence of dark matter; 3. the baryon asymmetry of the Universe. To address these problems, theories extending the lepton and/or Higgs sectors of the Standard Model are employed. Among these, one can distinguish neutrino mass generation mechanisms for standard (active) neutrinos, known in the literature as seesaw mechanisms. These solve the problem of small non-zero neutrino masses while also providing possible sources of baryon symmetry violation in the early Universe and predicting particles that could act as fermionic dark matter. In this work, we analyze three canonical seesaw mechanisms (Type-I, Type-II, and inverse seesaw). For each mechanism, we discuss: the possibility of describing dark matter, the generation of baryon asymmetry through electroweak baryogenesis and other cosmological implications. We investigate the allowed parameter ranges and potential interconnections between different types of mechanisms.