Previrialization

Abstract

We report the results of N-body experiments employing Gaussian random initial conditions designed to address the effect of previrialization recently examined by Peebles. The central issue is whether the development of small-scale structure within a collapsing protocluster can significantly retard its collapse. A series of runs with progressively diminished small-scale power indicates that the collapse of objects is insensitive to the degree of clustering on small scales. We conclude that previrialization does not have significant impact on the formation epoch of galaxies and clusters arising from gravitational clustering of initially Gaussian random density fields.