Velocity differences as a probe of non-Gaussian density fields

Abstract

We examine the multipoint linear velocity field for non-Gaussian models as a probe of non-Gaussian behavior. The two-point velocity correlation is not a useful indicator of a non-Gaussian density field, since it depends only on the power spectrum, even for non-Gaussian models. However, we show that the distribution of velocity differences v_1_ - v_2_, where v_1_ and v_2_ are measured at the points r_1_ and r_2_, respectively, is a good probe of non-Gaussian behavior, in that p(v_1_ - v_2_) tends to be non-Gaussian when the density field is non- Gaussian. As an example, we examine the behavior of p(v_1_ - v_2_) for non-Gaussian seed models, in which the density field is the convolution of a distribution of points with a set of density profiles. We apply these results to the global texture model.