The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: cosmological implications from two decades of Spectroscopic Surveys at the Apache Point observatory

Shadab Alam, Marie Aubert, Santiago Avila, Christophe Balland, Julian E. Bautista, Matthew A. Bershady, Dmitry Bizyaev, Michael R. Blanton, Adam S. Bolton, Jo Bovy, Jonathan Brinkmann, Joel R. Brownstein, Etienne Burtin, Solene Chabanier, Michael J. Chapman, Peter Doohyun Choi, Chia-Hsun Chuang, Johan Comparat, Andrei Cuceu, Kyle S. DawsonAxel de la Macorra, Sylvain de la Torre, Arnaud de Mattia, Victoria de Sainte Agathe, Hélion du Mas des Bourboux, Stephanie Escoffier, Thomas Etourneau, James Farr, Andreu Font-Ribera, Peter M. Frinchaboy, Sebastien Fromenteau, Héctor Gil-Marín, Alma X. Gonzalez-Morales, Violeta Gonzalez-Perez, Kathleen Grabowski, Julien Guy, Adam J. Hawken, Jiamin Hou, Hui Kong, Mark Klaene, Jean-Paul Kneib, Jean-Marc Le Goff, Sicheng Lin, Daniel Long, Brad W. Lyke, Marie-Claude Cousinou, Paul Martini, Karen Masters, Faizan G. Mohammad, Jeongin Moon, Eva-Maria Mueller, Andrea Munõz-Gutieŕrez, Adam D. Myers, Seshadri Nadathur, Richard Neveux, Jeffrey A. Newman, Pasquier Noterdaeme, Audrey Oravetz, Daniel Oravetz, Nathalie Palanque-Delabrouille, Kaike Pan, Parker III James, Romain Paviot, Will J. Percival, Ignasi Peŕez-Rafols, Patrick Petitjean, Matthew M. Pieri, Abhishek Prakash, Anand Raichoor, Corentin Ravoux, Mehdi Rezaie, James Rich, Ashley J. Ross, Graziano Rossi, Rossana Ruggeri, Vanina Ruhlmann-Kleider, Ariel G. Sańchez, F. Javier Sańchez, José R. Sańchez-Gallego, Conor Sayres, Donald P. Schneider, Hee-Jong Seo, Arman Shafieloo, Anže Slosar, Alex Smith, Julianna Stermer, Amelie Tamone, Jeremy L. Tinker, Rita Tojeiro, Mariana Vargas-Magaña, Andrei Variu, Yuting Wang, Benjamin A. Weaver, Anne-Marie Weijmans, Christophe Yeche, Pauline Zarrouk, Cheng Zhao, Gong-Bo Zhao, Zheng Zheng

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We present the cosmological implications from final measurements of clustering using galaxies, quasars, and Lyα forests from the completed Sloan Digital Sky Survey (SDSS) lineage of experiments in large-scale structure. These experiments, composed of data from SDSS, SDSS-II, BOSS, and eBOSS, offer independent measurements of baryon acoustic oscillation (BAO) measurements of angular-diameter distances and Hubble distances relative to the sound horizon, rd, from eight different samples and six measurements of the growth rate parameter, fσ8, from redshift-space distortions (RSD). This composite sample is the most constraining of its kind and allows us to perform a comprehensive assessment of the cosmological model after two decades of dedicated spectroscopic observation. We show that the BAO data alone are able to rule out dark-energy-free models at more than eight standard deviations in an extension to the flat, ΛCDM model that allows for curvature. When combined with Planck Cosmic Microwave Background (CMB) measurements of temperature and polarization, under the same model, the BAO data provide nearly an order of magnitude improvement on curvature constraints relative to primary CMB constraints alone. Independent of distance measurements, the SDSS RSD data complement weak lensing measurements from the Dark Energy Survey (DES) in demonstrating a preference for a flat ΛCDM cosmological model when combined with Planck measurements. The combined BAO and RSD measurements indicate σ8=0.85±0.03, implying a growth rate that is consistent with predictions from Planck temperature and polarization data and with General Relativity. When combining the results of SDSS BAO and RSD, Planck, Pantheon Type Ia supernovae (SNe Ia), and DES weak lensing and clustering measurements, all multiple-parameter extensions remain consistent with a ΛCDM model. Regardless of cosmological model, the precision on each of the three parameters, ΩΛ, H0, and σ8, remains at roughly 1%, showing changes of less than 0.6% in the central values between models. In a model that allows for free curvature and a time-evolving equation of state for dark energy, the combined samples produce a constraint Ωk=−0.0022±0.0022. The dark energy constraints lead to w0=−0.909±0.081 and wa=−0.49+0.35−0.30, corresponding to an equation of state of wp=−1.018±0.032 at a pivot redshift
zp=0.29 and a Dark Energy Task Force Figure of Merit of 94. The inverse distance ladder measurement under this model yields H0=68.18±0.79  km s−1 Mpc−1, remaining in tension with several direct determination methods; the BAO data allow Hubble constant estimates that are robust against the assumption of the cosmological model. In addition, the BAO data allow estimates of H0 that are independent of the CMB data, with similar central values and precision under a
ΛCDM model. Our most constraining combination of data gives the upper limit on the sum of neutrino masses at ∑mν<0.115  eV (95% confidence). Finally, we consider the improvements in cosmology constraints over the last decade by comparing our results to a sample representative of the period 2000–2010. We compute the relative gain across the five dimensions spanned by w, Ωk, ∑mν, H0, and σ8 and find that the SDSS BAO and RSD data reduce the total posterior volume by a factor of 40 relative to the previous generation. Adding again the Planck, DES, and Pantheon SN Ia samples leads to an overall contraction in the five-dimensional posterior volume of 3 orders of magnitude.
Original languageEnglish
Article number083533
Number of pages43
JournalPhysical Review D
Publication statusPublished - 28 Apr 2021


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