The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: a tomographic analysis of structure growth and expansion rate from anisotropic galaxy clustering

TL;DR

This paper conducts a detailed tomographic analysis of galaxy clustering from SDSS-III BOSS data to measure cosmic expansion and structure growth, providing precise constraints on cosmological parameters and testing gravity models.

Contribution

It introduces a novel tomographic approach analyzing nine redshift slices to jointly constrain key cosmological parameters from anisotropic galaxy clustering data.

Findings

Measured $D_V$, $F_{AP}$, and $f \sigma_8$ with high precision across redshifts.

Found the gravitational growth index $\gamma$ consistent with $\Lambda$CDM.

Validated analysis pipeline with mock catalogues.

Abstract

We perform a tomographic analysis of structure growth and expansion rate from the anisotropic galaxy clustering of the combined sample of Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, which covers the redshift range of $0.2<z<0.75$. In order to extract the redshift information of anisotropic galaxy clustering, we analyse this data set in nine overlapping redshift slices in configuration space and perform the joint constraints on the parameters $(D_V, F_{\mathrm{AP}}, f\sigma_8)$ using the correlation function multipoles. The analysis pipeline is validated using the MultiDark-Patchy mock catalogues. We obtain a measurement precision of $1.5\%-2.9\%$ for $D_V$, $5.2\%-9\%$ for $F_{\mathrm{AP}}$ and $13.3\%-24\%$ for $f \sigma_8$, depending on the effective redshift of the slices. We report a joint measurement of $(D_V, F_{\mathrm{AP}}, f\sigma_8)$ with the full covariance matrix in nine redshift slices. We use our joint BAO and RSD measurement combined with external datasets to constrain the gravitational growth index $\gamma$, and find $\gamma=0.656 \pm 0.057$, which is consistent with the $\Lambda$CDM prediction within 95\% CL.