An estimate of Omega(m) without conventional priors

Abstract

Using mean relative peculiar velocity measurements for pairs of galaxies, we estimate the cosmological density parameter and the amplitude of density fluctuations j8 Qm . Our results suggest that our statistic is a robust and reproducible measure of the mean pairwise velocity and thereby the parameter. We get and 0.17 Q Q m m p 0.300.07 . These estimates do not depend on prior assumptions on the adiabaticity of the initial density 0.22 j8 p 1.130.23 fluctuations, the ionization history, or the values of other cosmological parameters.