The TeV mass curvaton

Abstract

We consider the constraints for a curvaton with massm ∼ \U0001d4aa(1) TeV and show that they are not consistentwith a purely quadratic potential. Even if the curvatonself-interactions are very weak, they must be accounted for as theyaffect the dynamical evolution of the curvature perturbation. Weshow that the only monomial self-interaction for a TeV-mass curvaton that(a) yields the correct perturbation amplitude, (b) decays before thedark matter freeze-out, and (c) does not give rise to non-Gaussianperturbations that would be in conflict with the present limits, is givenby Vint = σ8/M4. The decay width of the curvatonshould be in the range Γ = 10−15−10−17 GeV. The model typically predicts large non-linearity parameters fNL and gNL that should be observable by the Plancksatellite. We also discuss various physical possibilities to obtain the required small curvaton decay rate.