C³ Cluster Clustering Cosmology I. New Constraints on the Cosmic Growth Rate at z ∼ 0.3 from Redshift-space Clustering Anisotropies

Abstract

Abstract Redshift-space distortions in the clustering of galaxy clusters provide a novel probe to test the theory of gravity on cosmological scales. The aim of this work is to derive new constraints on the linear growth rate of cosmic structures from the redshift-space two-point correlation function of galaxy clusters. We construct a large spectroscopic catalog of optically selected clusters from the Sloan Digital Sky Survey. The selected sample consists of 43,743 clusters in the redshift range 0.1 < z < 0.42, with masses estimated from weak-lensing calibrated scaling relations. We measure the transverse and radial wedges of the two-point correlation function of the selected clusters. Modeling the redshift-space clustering anisotropies, we provide the first constraints on the linear growth rate from cluster clustering. The cluster masses are used to set a prior on the linear bias of the sample. This represents the main advantage in using galaxy clusters as cosmic probes, instead of galaxies. Assuming a standard cosmological model consistent with the latest cosmic microwave background constraints, we do not find any evidence of deviations from general relativity. Specifically, we get the value of the growth rate times the matter power spectrum normalization parameter fσ 8 = 0.44 ± 0.05, at an effective redshift of z = 0.275.