Leptogenesis via Neutrino Oscillation Magic
  The possibility of generating the baryon asymmetry of the Universe via flavor
oscillation in the early Universe is discussed. After the inflation, leptons
are born in some states, travel in the medium, and are eventually projected
onto flavor eigenstates due to the scattering via the Yukawa interactions. By
using the Lagrangian of the Standard Model with the Majorana neutrino mass
terms, llHH, we follow the time evolution of the density matrices of the
leptons in this very first stage of the Universe and show that the CP violation
in the flavor oscillation can explain the baryon asymmetry of the Universe. In
the scenario where the reheating is caused by the decay of the inflaton into
the Higgs bosons, the baryon asymmetry is generated by the CP phases in the
Pontecorvo-Maki-Nakagawa-Sakata matrix and thus can be tested by the low energy
neutrino experiments.
