Cosmic Velocities 2000: A Review

Abstract

I review the status of cosmic velocity analysis as of January 2000, with an emphasis on two key questions: (1) What is the scale of the largest bulk flows in the universe? and (2) What is the value of beta=Omega_m^{0.6}/b indicated by cosmic velocities, and what does this tell us about Omega_m itself? These are the most important issues for cosmic flow analysis, and each has been controversial in recent years. I argue that a preponderance of the evidence at present argues against very large scale (> 100 Mpc) bulk flows, and favors beta = 0.4-0.5, corresponding to a low-density (Omega_m=0.2-0.3) universe.