Neutrino-Antineutrino Asymmetry around Rotating Black Holes

Abstract

Propagation of fermion in curved space-time generates gravitational interaction due to the coupling between spin of the fermion and space-time curvature. This gravitational interaction, which is an axial-vector appears as CPT violating term in the Lagrangian. It is seen that this space-time interaction can generate neutrino asymmetry in Universe. If the back-ground metric is spherically asymmetric, say, of a rotating black hole, this interaction is non-zero, thus the net difference to the number density of the neutrino and anti-neutrino is nonzero.

3 pages, pramana style; to appear in a special issue of Pramana -- J. Phys., as proceedings of IXth Particle-String-Cosmology (PASCOS), January 3-8, 2003, TIFR, Mumbai, India