TOPOLOGY OF LARGE-SCALE STRUCTURE IN SEEDED HOT DARK MATTER MODELS

We examine the topology of the isodensity surfaces in seeded hot dark matter models, in which static seed masses provide the density perturbations in a universe dominated by massive neutrinos. When smoothed with a Gaussian window W(r) = e(-r2/r0(2)), the linear initial conditions in these models show no trace of non-Gaussian behavior for r0 greater-than-or-equal-to 5 Mpc (h = 1/2), except for very low seed densities, which show a shift toward isolated peaks. An approximate analytic expression is given for the genus curve expected in linear density fields from randomly distributed seed masses. The evolved models have a Gaussian topology for r0 = 10 Mpc, but show a shift toward a cellular topology with r0 = 5 Mpc; Gaussian models with an identical power spectrum show the same behavior. Contour plots can distinguish between the seeded hot dark matter model and the Gaussian model with an identical initial power spectrum: after equal evolution in the expansion factor, the seeded hot dark matter model produces more coherent structure; the high-density regions form a network of connected filaments, while the low-density regions in this model are made up of large well-defined voids.