SBi3PCF: cosmology with Dark Energy Survey Year 3 cosmic shear
Abstract
We present the first cosmic shear data analysis of the integrated 3-point correlation function (i3PCF), a higher-order weak lensing statistic, and the first simulation-based inference (SBI) analysis of a three-point cosmic shear correlation function on survey data. Using SBi3PCF, our previously developed SBI framework for the i3PCF, we jointly constrain the wCDM parameter space with the cosmic shear 2-point correlation functions ξ± (2PCFs) and the i3PCFs ζ± from the Dark Energy Survey Year 3 (DES Y3) weak lensing shape catalogue, from which we detect ζ± with a signal-to-noise ratio of 12.8. Our forward model is built on the CosmoGridV1 N-body simulations and includes the survey mask, shape noise, intrinsic alignment, baryonic feedback, photometric redshift uncertainty and shear calibration bias. The analysis was carried out blind, with all choices frozen, and only unblinded once coverage tests, tests of the accuracy of the learned likelihoods, and internal consistency tests had been passed. For the joint ξ± + ζ± analysis we obtain Ωm = 0.272+0.038−0.033, S8 = 0.784+0.024−0.021 and w0 = −1.04+0.25−0.19. Adding ζ± improves the figure of merit in the Ωm-S8-w0 parameter space by a factor of $1.59$ over ξ± alone, as predicted by simulated i3PCF analyses. This gain comes from third-order information on angular scales ≥ 15' and aperture radii ≥ 50', a regime where baryonic effects are subdominant. The constraints are consistent with the other DES Y3 analyses of the same catalogue and with independent lensing analyses, and differ by at most 2.4σ from CMB and BAO data (Planck 2018 + BAO, in Ωm-S8-w0). This shows that ζ± can be analysed on cosmological survey data with a fully simulation-based approach, an important step towards Stage-IV surveys.
Related
- photo-3x2-pt: Cosmology from cosmic shear and galaxy clustering with a single photometric galaxy catalog
- Dark Energy Survey Year 6 Results: fast and interpretable posterior predictive checks for correlated cosmic probes
- Topological Defects in Cosmic Shear
- Joint measurements of thermal Sunyaev-Zel'dovich and cosmic infrared background cross-correlations with cosmic shear
- Baryonic feedback and intrinsic alignments in profile: a frequentist view of DES Y3 cosmic shear
BibTeX
@misc{gebauer2026sbi3pcf,
title = {{SBi3PCF: cosmology with Dark Energy Survey Year 3 cosmic shear}},
author = {David Gebauer and Anik Halder and Zhengyangguang Gong and Cora Uhlemann},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.05367},
eprint = {2611.05367},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.05367},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - SBi3PCF: cosmology with Dark Energy Survey Year 3 cosmic shear
AU - David Gebauer
AU - Anik Halder
AU - Zhengyangguang Gong
AU - Cora Uhlemann
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.05367
UR - https://arxiv.org/abs/2611.05367
AB - We present the first cosmic shear data analysis of the integrated 3-point correlation function (i3PCF), a higher-order weak lensing statistic, and the first simulation-based inference (SBI) analysis of a three-point cosmic shear correlation function on survey data. Using SBi3PCF, our previously developed SBI framework for the i3PCF, we jointly constrain the wCDM parameter space with the cosmic shear 2-point correlation functions ξ_± (2PCFs) and the i3PCFs ζ_± from the Dark Energy Survey Year 3 (DES Y3) weak lensing shape catalogue, from which we detect ζ_± with a signal-to-noise ratio of 12.8. Our forward model is built on the CosmoGridV1 N-body simulations and includes the survey mask, shape noise, intrinsic alignment, baryonic feedback, photometric redshift uncertainty and shear calibration bias. The analysis was carried out blind, with all choices frozen, and only unblinded once coverage tests, tests of the accuracy of the learned likelihoods, and internal consistency tests had been passed. For the joint ξ_± + ζ_± analysis we obtain Ω_m = 0.272^+0.038_−0.033, S_8 = 0.784^+0.024_−0.021 and w_0 = −1.04^+0.25_−0.19. Adding ζ_± improves the figure of merit in the Ω_m-S_8-w_0 parameter space by a factor of $1.59$ over ξ_± alone, as predicted by simulated i3PCF analyses. This gain comes from third-order information on angular scales ≥ 15' and aperture radii ≥ 50', a regime where baryonic effects are subdominant. The constraints are consistent with the other DES Y3 analyses of the same catalogue and with independent lensing analyses, and differ by at most 2.4σ from CMB and BAO data (Planck 2018 + BAO, in Ω_m-S_8-w_0). This shows that ζ_± can be analysed on cosmological survey data with a fully simulation-based approach, an important step towards Stage-IV surveys.
ER -