On the pattern of perturbations of the Hubble flow

Abstract

The average pattern expected for the large-scale distortions of the Hubble flow driven by gravitational instability is examined. Both bulk flow and shearing motions are considered and the probability distributions for observed radial velocities are presented. Statistical tools are introduced that can be used in galaxy peculiar velocity data analysis to distinguish between different competing scenarios for the evolution of large-scale structure in the universe. These statistical measures are very sensitive to differences in power spectra of primordial inhomogeneities when applied in a distance regime accessible to ongoing observational programs.