The Clustering of the SDSS-IV Extended Baryon Oscillation Spectroscopic Survey DR14 Quasar Sample: A Tomographic Measurement of Cosmic Structure Growth and Expansion Rate based on Optimal Redshift Weights


We develop a new method, which is based on the optimal redshift weighting scheme, to extract the maximal tomographic information of baryonic acoustic oscillations (BAO) and redshift space distortions (RSD) from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 14 quasar (DR14Q) survey. We validate our method using the Extended Zel'dovich mocks, and apply our pipeline to the eBOSS DR14Q sample in the redshift range of 0.8 < z < 2.2. We report a joint measurement of fσ8 and two-dimensional BAO parameters DA and H at four effective redshifts of zeff = 0.98, 1.23, 1.52, and 1.94, and provide the full data covariance matrix. Using our measurement combined with BOSS DR12, Main Galaxy Sample (MGS), and 6 degree Field Galaxy Survey (6dFGS) BAO measurements, we find that the existence of dark energy is supported by observations at a 7.4σ significance level. Combining our measurement with BOSS DR12 and Planck observations, we constrain the gravitational growth index to be γ = 0.580 ± 0.082, which is fully consistent with the prediction of general relativity. This paper is part of a set that analyses the eBOSS DR14 quasar sample.



Keywords and Phrases

Cosmological parameters; Dark energy; Distance scale; Large-scale structure of Universe

International Standard Serial Number (ISSN)

0035-8711; 1365-2966

Document Type

Article - Journal

Document Version


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© 2019 Oxford University Press, All rights reserved.

Publication Date

01 Jan 2019