Dark Energy Survey Year 3 results: Cosmological constraints from galaxy clustering and weak lensing

Abstract

We present the first cosmology results from large-scale structure using the full 5000 deg(2) of imaging data from the Dark Energy Survey (DES) Data Release 1. We perform an analysis of large-scale structure combining three two-point correlation functions (3 x 2pt): (i) cosmic shear using 100 million source galaxies, (ii) galaxy clustering, and (iii) the cross-correlation of source galaxy shear with lens galaxy positions, galaxy-galaxy lensing. To achieve the cosmological precision enabled by these measurements has required updates to nearly every part of the analysis from DES Year 1, including the use of two independent galaxy clustering samples, modeling advances, and several novel improvements in the calibration of gravitational shear and photometric redshift inference. The analysis was performed under strict conditions to mitigate confirmation or observer bias; we describe specific changes made to the lens galaxy sample following unblinding of the results and tests of the robustness of our results to this decision. We model the data within the flat Lambda CDM and wCDM cosmological models, marginalizing over 25 nuisance parameters. We find consistent cosmological results between the three two-point correlation functions; their combination yields clustering amplitude S-8 = 0.776(-0.017)(+0.017) and matter density Omega(m) = 0.339(-0.031)(+0.032) in Lambda CDM, mean with 68% confidence limits; S-8 = 0.775(-0.024)(+0.026), Omega(m) = 0.352(-0.041)(+0.035), and dark energy equation-of-state parameter w = -0.98(-0.02)(+0.32) in wCDM. These constraints correspond to an improvement in signal-to-noise of the DES Year 33 x 2pt data relative to DES Year 1 by a factor of 2.1, about 20% more than expected from the increase in observing area alone. This combination of DES data is consistent with the prediction of the model favored by the Planck 2018 cosmic microwave background (CMB) primary anisotropy data, which is quantified with a probability-to-exceed p = 0.13-0.48. We find better agreement between DES 3 x 2pt and Planck than in DES Y1, despite the significantly improved precision of both. When combining DES 3 x 2pt data with available baryon acoustic oscillation, redshift-space distortion, and type la supernovae data, we find p = 0.34. Combining all of these datasets with Planck CMB lensing yields joint parameter constraints of S-8 = 0.812(-0.008)(+0.008), Omega(m) = 0.306(-0.005)(+0.004), h = 0.680(-0.003)(+0.004), and Sigma m(nu) < 0.13 eV (95% C.L.) in Lambda CDM; S-8 = 0.812(-0.008)(+0.008), Omega(m) = 0.302(-0.006)(+0.006), h = 0.687(-0.007)(+0.006), and w = -1.031(-0.027)(+0.030) in wCDM.

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Affiliated Institutions

• University of Wisconsin–Madison US
• Université Paris Cité FR
• Jet Propulsion Laboratory US
• University of Manchester GB
• Sorbonne Université FR
• Kavli Institute for Particle Astrophysics and Cosmology US
• Cerro Tololo Inter-American Observatory CL
• University College London GB
• Universidade Estadual Paulista (Unesp) BR
• National Observatory BR
• Carnegie Mellon University US
• Australian National University AU
• Universidad de La Laguna ES
• Lowell Observatory US
• Universidade de São Paulo BR
• Fermi National Accelerator Laboratory US
• University of Pennsylvania US
• Duke University US
• University of Oslo
• Institute for High Energy Physics ES
• Ludwig-Maximilians-Universität München DE
• University of Edinburgh GB
• Universidad Autónoma de Madrid ES
• The University of Texas at Austin US
• Macquarie University AU
• Centre National de la Recherche Scientifique FR
• Perimeter Institute CA
• University of Illinois Urbana-Champaign US
• Australian Astronomical Observatory AU
• Valongo Observatory BR
• The University of Queensland AU
• University of Arizona US
• Institute of Space Sciences ES
• Indian Institute of Technology Hyderabad IN
• Institut d'Estudis Espacials de Catalunya ES
• University of Trieste IT
• University of Sussex GB
• University of Hawaii System US
• Trieste Astronomical Observatory IT
• Université Paris Sciences et Lettres FR
• École Normale Supérieure - PSL FR
• Argonne National Laboratory US
• Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas ES
• Lawrence Berkeley National Laboratory US
• UK Astronomy Technology Centre GB
• University of Cambridge GB
• National Center for Supercomputing Applications US
• Universidade Estadual de Campinas (UNICAMP) BR
• University of Geneva CH
• Northeastern University US
• University of Oxford GB
• École Polytechnique Fédérale de Lausanne CH
• University of Lisbon PT
• University of Nottingham GB
• Instituto de Astrofísica de Canarias ES
• Center for Astrophysics Harvard & Smithsonian US
• University of Chicago US
• Institute of Astrophysics and Space Sciences PT
• Stanford University US
• Institute for Physics US
• SLAC National Accelerator Laboratory US
• University of Michigan US
• The Ohio State University US
• University of Portsmouth GB
• Institute for Fundamental Physics of the Universe IT
• Laboratório Interinstitucional de e-Astronomia BR

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