Higgs-Lepton Inflation in the Supersymmetric Minimal Seesaw Model
We investigate a scenario of cosmological inflation realized along a flat direction of the minimal seesaw model embedded in supergravity with a noncanonical R-parity violating Kähler potential. It is shown that with appropriate seesaw parameters the model is consistent with the present observation of the cosmological microwave background as well as with the neutrino oscillation data. It is also shown that the baryon asymmetry of the Universe can be generated through leptogenesis. The model favors supersymmetry breaking with the gravitino as the lightest superparticle, and thus indicates the gravitino dark matter scenario. An interesting feature of this model is that the seesaw parameters are constrained by the cosmological microwave background spectra. The 2−σ constraints from the 9-year WMAP data yield a mild lower bound on the seesaw mass scale ≳ TeV. We expect that the observation by the Planck satellite will soon provide more stringent constraints. The phenomenological and cosmological implications of the R-parity violation are also discussed.