Non-Gaussianity and constraints for the variance of perturbations in the curvaton model

摘要: Recently, the primordial non-Gaussianity in curvaton model has been predicted assuming sudden decay of curvaton. We extend calculation to non-instantaneous by employing delta N -formalism. The difference between sudden-decay approximation and our numerical result is larger than 1% only if non-linearity parameter small, -1.16 / \sigma_0^2$ assumed be negligible. However, measurements CMB or large-scale structure perturbation amplitude do not constrain variance main contribution it comes from ultraviolet (UV) scales, i.e., smaller observable scales. discuss how, even this case, observational constraints on set an upper bound small scale variance, Delta^2_UV < 90.