Dark Energy Survey Year 3 results: Cosmology from cosmic shear and robustness to modeling uncertainty

This work and its companion paper, Amon et al. [Phys. Rev. D 105, 023514 (2022)], present cosmic shear measurements cosmological constraints from over 100 million source galaxies in the Dark Energy Survey (DES) Year 3 data. We constrain lensing amplitude parameter S8≡σ8Ωm/0.3 at 3% level ΛCDM: S8=0.759−0.023+0.025 (68% CL). Our constraint is 2% when using angular scale cuts that are optimized for ΛCDM analysis: S8=0.772−0.017+0.018 With alone, we find no statistically significant on dark energy equation-of-state our statistical power. carry out analysis blind, compare measurement with two other contemporary weak experiments: Kilo-Degree (KiDS) Hyper-Suprime Camera Subaru Strategic Program (HSC). additionally quantify agreement between data external Cosmic Microwave Background (CMB). DES Y3 result under assumption of found to be Planck 2018, although favors a lower S8 than CMB-inferred value by 2.3σ (a p-value 0.02). paper explores robustness these results modeling intrinsic alignments, matter power spectrum baryonic physics. explore preference alignment models different complexity. The fiducial model tested synthetic data, report biases greater 0.3σ plane S8×Ωm caused uncertainties theoretical models.10 MoreReceived 25 June 2021Accepted 30 November 2021Corrected 6 April 2022DOI:https://doi.org/10.1103/PhysRevD.105.023515© 2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCosmological parametersGravitational lensesSky surveysGravitation, Cosmology & Astrophysics