Dark Energy Survey Year 3 results: Cosmological constraints from galaxy clustering and weak lensing
Abstract
We present the first cosmology results from largescale structure using the full 5000 deg^{2} of imaging data from the Dark Energy Survey (DES) Data Release 1. We perform an analysis of largescale structure combining three twopoint correlation functions (3 ×2 pt ): (i) cosmic shear using 100 million source galaxies, (ii) galaxy clustering, and (iii) the crosscorrelation of source galaxy shear with lens galaxy positions, galaxygalaxy 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 Λ CDM and w CDM cosmological models, marginalizing over 25 nuisance parameters. We find consistent cosmological results between the three twopoint correlation functions; their combination yields clustering amplitude S_{8}=0.77 6_{0.017}^{+0.017} and matter density Ω_{m}=0.33 9_{0.031}^{+0.032} in Λ CDM , mean with 68% confidence limits; S_{8}=0.77 5_{0.024}^{+0.026}, Ω_{m}=0.35 2_{0.041}^{+0.035}, and dark energy equationofstate parameter w =0.9 8_{0.20}^{+0.32} in w CDM . These constraints correspond to an improvement in signaltonoise of the DES Year 3 3 ×2 pt 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 probabilitytoexceed p =0.13 0.48. We find better agreement between DES 3 ×2 pt and Planck than in DES Y1, despite the significantly improved precision of both. When combining DES 3 ×2 pt data with available baryon acoustic oscillation, redshiftspace distortion, and type Ia supernovae data, we find p =0.34 . Combining all of these datasets with Planck CMB lensing yields joint parameter constraints of S_{8}=0.81 2_{0.008}^{+0.008}, Ω_{m}=0.30 6_{0.005}^{+0.004}, h =0.68 0_{0.003}^{+0.004}, and ∑m_{ν}<0.13 eV (95% C.L.) in Λ CDM ; S_{8}=0.81 2_{0.008}^{+0.008}, Ω_{m}=0.30 2_{0.006}^{+0.006}, h =0.68 7_{0.007}^{+0.006}, and w =1.03 1_{0.027}^{+0.030} in w CDM .
 Publication:

Physical Review D
 Pub Date:
 January 2022
 DOI:
 10.1103/PhysRevD.105.023520
 arXiv:
 arXiv:2105.13549
 Bibcode:
 2022PhRvD.105b3520A
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 See https://www.darkenergysurvey.org/desyear3cosmologyresultspapers/ for the full DES Y3 3x2pt cosmology release. Matches version accepted in PRD