Non-Gaussian Initial Conditions in Cosmological N-body Simulations: I. Space-Uncorrelated Models

Results are reported on N-body simulations of the large-scale structure of the universe starting from non-Gaussian space-uncorrelated initial conditions. Specifically, two hierarchical models and the lognormal statistics for the initial probability distribution are considered. These models share two common properties: they fulfil the positive mass constraint (delta-M is not less than -1) and they have positive skewness. The resulting distributions, both in space and velocity, are analyzed by means of many statistical tests, and compared with an evolved reference Poisson model. The different starting conditions keep their effects after many expansion times, as shown by the cluster analysis and by the quadrupole statistics; the evolved non-Gaussian distributions show the existence of elongated and/or flattened configurations in excess of the evolved Poisson model. The velocity field, analyzed in terms of the cosmic Mach number, does not reveal relevant changes with respect to the initially Gaussian model.