Gravitationally induced neutrino asymmetry

Abstract

We study the propagation of Dirac neutrinos in gravitational backgrounds and show that the gravitational interaction can lead to neutrino asymmetry due to modi cations in dispersion relation. We give some examples of spacetime geometries where such asym- metry can arise. This asymmetry would have contributed to the relic neutrino asymmetry through the interaction of neutrinos with primordial black holes before neutrinos decou- pled. In the present epoch it may be generated in accretion around high temperature rotating black holes.