Mixed inflaton and curvaton scenario with sneutrinos

TL;DR

This paper explores a mixed inflaton-curvaton model using sneutrinos with a chi^2 potential, showing how late-decaying sneutrinos can dilute gravitinos, generate matter asymmetry, and influence CMB observables.

Contribution

It introduces a novel mixed inflaton-curvaton scenario with sneutrinos, highlighting how different initial conditions affect CMB signatures and cosmological outcomes.

Findings

Late-decaying sneutrino dilutes gravitinos.

Sneutrino contributes to curvature perturbation.

CMB observations can distinguish scenarios based on initial sneutrino value.

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.