An estimate of Ω_m without priors

Using mean relative peculiar velocity measurements for pairs of galaxies, we estimate the cosmological density parameter $\Omega_m$ and the amplitude of density fluctuations $\sigma_8$. Our results suggest that our statistic is a robust and reproducible measure of the mean pairwise velocity and ther...

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Bibliographic Details
Main Authors: Feldman, H, Juszkiewicz, R, Ferreira, P, Davis, M, Gaztanaga, E, Fry, J, Jaffe, A, Chambers, S, Costa, L, Bernardi, M, Giovanelli, R, Haynes, M, Wegner, G
Format: Journal article
Published: 2003
Description
Summary:Using mean relative peculiar velocity measurements for pairs of galaxies, we estimate the cosmological density parameter $\Omega_m$ and the amplitude of density fluctuations $\sigma_8$. Our results suggest that our statistic is a robust and reproducible measure of the mean pairwise velocity and thereby the $\Omega_m$ parameter. We get $\Omega_m = 0.30^{+0.17}_{-0.07}$ and $\sigma_8 = 1.13^{+0.22}_{-0.23}$. These estimates do not depend on prior assumptions on the adiabaticity of the initial density fluctuations, the ionization history, or the values of other cosmological parameters.