Hierarchical Object Formation in the Peculiar Velocity Field

Using the initial peculiar velocity field, we analytically study the hierarchical formation of gravitationally bound objects. The field is smoothed over a scale that corresponds to the mass of a given class of objects. Through the Zelʹdovich approximation, the smoothed field determines how the objects cluster together to form a new class of more massive objects. The standard cosmological parameters lead to the evolution of primordial clouds with <106 M(circled dot operator)- galaxies with 1012 M(circled dot operator)clusters of galaxies with 10^15 M(circled dot operator)- superclusters of galaxies with 1016 M(circled dot operator). The epochs obtained for the formation of these classes of objects are consistent with observations.