Testing ΛCDM at the lowest redshifts with SN la and galaxy velocities

Peculiar velocities of objects in the nearby universe are correlated due to the gravitational pull of large-scale structure. By measuring these velocities, we have a unique opportunity to test the cosmological model at the lowest redshifts. We perform this test, using current data to constrain the amplitude of the signal covariance matrix describing the velocities and their correlations. We consider a new, well-calibrated Supercal set of low-redshift SNe Ia as well as a set of distances derived from the fundamental plane relation of 6dFGS galaxies. Analyzing the SN and galaxy data separately, both results are consistent with the peculiar velocity signal of our fiducial Lambda CDM model, ruling out the noise-only model with zero peculiar velocities at greater than 7 sigma (SNe) and 8 sigma (galaxies). When the two data sets are combined appropriately, the precision of the test increases slightly, resulting in a constraint on the signal amplitude of A = 1:05(-0.21) (+0.2 5,) where A = 1 corresponds to our fiducial model. Equivalently, we report an 11% measurement of the product of the growth rate and amplitude of mass fluctuations evaluated at z(eff) = 0.02, f sigma 8 = 0.428(-0.045)(+0.048), valid for our fiducial Lambda CDM model. We explore the robustness of the results to a number of conceivable variations in the analysis and find that individual variations shift the preferred signal amplitude by less than similar to 0.5 sigma. We briefly discuss our Supercal SN Ia results in comparison with our previous results using the JLA compilation.