Abstract

I will review some aspects of neutrino physics that may be relevant for the Physics of the Early Universe. In particular I will discuss: (i) the connection of (right-handed) Majorana neutrinos to Leptogenesis and Baryogenesis, thereby providing an explanation for the generation of the observed Baryon Asymmetry in the Universe, (ii) a possible connection of Majorana right-handed neutrinos to Dark matter and the associated astrophysical, cosmological and oscillation constraints, (iii) the formation of neutrino condensates in the Early Universe and links to dark energy, and (iv) the propagation of neutrinos in CPT Violating geometries of the Early Universe and the possibility of Leptogenesis/Baryogenesis without the need for enhanced CP violation. If the time allows, I will also discuss novel ways of generating masses for the right-handed neutrinos, lying in the right ball park for the lightest of these states (keV) to play a consistent cosmological role as dark matter, that go beyond the traditional see-saw mechanisms. These are associated with global anomalies, such as those arising in some geometries with torsion. In such scenarios, Majorana right-handed neutrino masses are generated at three loops, as a consequence of the mixing of a torsion pseudoscalar field with an axion, coupling to neutrinos via chirality-changing Yukawa couplings.