Mixed inflaton and curvaton scenario with sneutrinos

Abstract

A variation of sneutrino inflation based on chi^2 potential is considered where the inflaton and the late-decaying field are sneutrinos of different generations. The lighter, late-decaying sneutrino dilutes the gravitinos over-produced after inflaton decay and generates the matter asymmetry. It can also significantly contribute to the curvature perturbation, realizing the mixed inflaton-curvaton case. The cosmic microwave background (CMB) observables can distinguish this case from inflation with chi^2 potential, provided that the initial value of the late-decaying sneutrino is either an order of magnitude smaller or larger than the reduced Planck scale.

Comments: 1+15 pages, 3 figures, 1 table. v2: minor revision, references added. v3: removed a remark on the decoupling of a RH neutrino from the conclusion, added some explanations and references, matches version accepted by JCAP