VELOCITY DIFFERENCES AS A PROBE OF NON-GAUSSIAN DENSITY FIELDS

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.