The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the luminous red galaxy sample from the anisotropic correlation function between redshifts 0.6 and 1

Abstract

We present the cosmological analysis of the configuration-space anisotropic clustering in the completed Sloan Digital Sky Survey IV (SDSS-IV) extended Baryon Oscillation Spectroscopic Survey (eBOSS) DR16 galaxy sample. This sample consists of luminous red galaxies (LRGs) spanning the redshift range \(0.6 < z < 1\), at an effective redshift of \(z_{\rm eff}=0.698\). It combines 174 816 eBOSS LRGs and 202 642 BOSS CMASS galaxies. We extract and model the baryon acoustic oscillations (BAO) and redshift-space distortions (RSD) features from the galaxy two-point correlation function to infer geometrical and dynamical cosmological constraints. The adopted methodology is extensively tested on a set of realistic simulations. The correlations between the inferred parameters from the BAO and full-shape correlation function analyses are estimated. This allows us to derive joint constraints on the three cosmological parameter combinations: \(D_M(z)/r_d\), \(D_H(z)/r_d\) and \(f\sigma_8(z)\), where \(D_M\) is the comoving angular diameter distance, \(D_H\) is Hubble distance, \(r_d\) is the comoving BAO scale, \(f\) is the linear growth rate of structure, and \(\sigma_8\) is the amplitude of linear matter perturbations. After combining the results with those from the parallel power spectrum analysis of Gil-Marin et al. 2020, we obtain the constraints: \(D_M/r_d = 17.65 \pm 0.30\), \(D_H/r_d = 19.77 \pm 0.47\), \(f\sigma_8 = 0.473 \pm 0.044\). These measurements are consistent with a flat \(\Lambda\)CDM model with standard gravity.