An estimation of the local growth rate from Cosmicflows peculiar velocities

This article explores three usual estimators, noted as v12 of the pairwise velocity, ψ1 and ψ2 of the observed two-point galaxy peculiar velocity correlation functions. These estimators are tested on mock samples of Cosmicflows-3 data set (Tully, Courtois & Sorce), derived from a numerical cosmological simulation, and also on a number of constrained realizations of this data set. Observational measurements errors and cosmic variance are taken into consideration in the study. The result is a local measurement of fσ8 = 0.43(± 0.03)obs(± 0.11)cosmic out to z = 0.05, in support of a ΛCDM cosmology.