Neutrino coupling to cosmological background: A review on gravitational Baryo/Leptogenesis

In this work we review the theories of origin of matter-antimatter asymmetry in the Universe. The general conditions for achieving baryogenesis and leptogenesis in a CPT conserving field theory have been laid down by Sakharov. In this review we discuss scenarios where a background scalar or gravitational field spontaneously breaks the CPT symmetry and splits the energy levels between particles and anti-particles. Baryon or Lepton number violating processes in proceeding at thermal equilibrium in such backgrounds gives rise to Baryon or Lepton number asymmetry.Comment: 62 pages, no figures. Invited review to appear in IJMP

Neutrino processes with power law dispersion relations

We compute various processes involving neutrinos in the initial and/or final state and we assume that neutrinos have energy momentum relation with a general power law $E^2 =p^2+ \xi_n p^n$ correction due to Lorentz invariance violation. We find that for $n>2$ the bounds on $\xi_n$ from direct time of flight measurement are much more stringent than from constraining the neutrino Cerenkov decay process.Comment: 13 pages, 1 figure, Title change, replacement matches version accepted in Phys. Rev.