On the Morphology of Density Perturbations

Abstract

The morphological distribution of primordial density peaks is assessed. Previous determinations, those of Peacock & Heavens (1985) and those of Bardeen et al (1986) have contradictory concluded that there exist a tendency towards prolate or towards oblate shapes, respectively. By using two methods, the Hessian and the inertia tensor momenta we have performed numerical determinations of the triaxiality of density perturbations in Gaussian random fields with power law spectra. We show that there is no present any tendency of shapes, and that the triaxiality distribution is independent of the spectral index. Moreover, it is shown that the results of Peacock and Heavens are compatible with our determinations. These results are in complete agreement with current triaxial distributions inferred for galaxies and clusters both, from observations and from numerical simulations.