Non-Gaussianity and Baryonic Isocurvature Fluctuations in the Curvaton Scenario

Understand

We discuss non-Gaussianity and baryonic isocurvature fluctuations in the curvaton scenario, assuming that the baryon asymmetry of the universe originates only from the decay products of the inflaton.

• When large non-Gaussianity is realized in such a scenario, non-vanishing baryonic isocurvature fluctuations can also be generated unless the baryogenesis occurs after the decay of the curvaton.
• We calculate the non-linearity parameter f_NL and the baryonic isocurvature fluctuations, taking account of the primordial fluctuations of both the inflaton and the curvaton.
• We show that, although current constraints on isocurvature fluctuations are severe, the non-linearity parameter can be large as f_NL \sim O(10-100) without conflicting with the constraints.