Skewness as a probe of non-Gaussian initial conditions

Abstract

We compute the skewness of the matter distribution arising from non-linear evolution and from non-Gaussian initial perturbations. We apply our result to a very generic class of models with non-Gaussian initial conditions and we estimate analytically the ratio between the skewness due to non-linear clustering and the part due to the intrinsic non-Gaussianity of the models. We finally extend our estimates to higher moments.

Figures (1)

• Figure 1: The coherent approximation (dashed line) and the full decoherent result (solid line) for the 2- (top) and 3-point (bottom) functions of the large-N limit of global $O(N)$ symmetric scalar fields is shown at the end of the radiation era. The sign in the coherent approximation for the 3-point function is chosen to agree with the sign for the decoherent 3-point function.