Chaotic Inflation with Right-handed Sneutrinos after Planck

We propose a chaotic inflation model in which the lightest right-handed sneutrino serves as the inflaton and the predicted values of the spectral index and tensor-to-scalar ratio are consistent with the Planck data. Interestingly, the observed magnitude of primordial density perturbations is naturally explained by the inflaton mass of order $10^{13}$GeV, which is close to the right-handed neutrino mass scale suggested by the seesaw mechanism and the neutrino oscillation experiments. We find that the agreement of the two scales becomes even better in the neutrino mass anarchy. We show that the inflation model can be embedded into supergravity and discuss thermal history of the Universe after inflation such as non-thermal leptogenesis by the right-handed sneutrino decays and the modulus dynamics.