Higher order moments of the density field in a parameterized sequence of non-gaussian theories

Abstract

We calculate the higher order moments in a sequence of models where the initial density fluctuations are drawn from a chi^2_nu distribution with a power-law power spectrum. For large values of nu the distribution is approximately gaussian, and we reproduce the values known from perturbation theory. As \nu is lowered the distribution becomes progressively more non-gaussian, approximating models with rare, high-amplitude peaks. The limit nu=1 is a realization of recently proposed isocurvature models for producing early galaxy formation where the density perturbations are quadratic in a gaussian field.