Simulation-based inference with the integrated 3PCF
arXiv:2510.13805 · doi:10.1088/1475-7516/2026/06/036
Abstract
We present , a simulation-based inference (SBI) framework for analysing a higher-order weak lensing statistic, the integrated 3-point correlation function (i3PCF). Our approach forward-models the cosmic shear field using the suite of N-body simulations, including a comprehensive set of systematic effects such as intrinsic alignment, baryonic feedback, photometric redshift uncertainty, shear calibration bias, and shape noise. Using this, we have produced a set of DES Y3-like synthetic measurements for 2-point shear correlation functions (2PCFs) and i3PCFs across 6 cosmological and 11 systematic parameters. Having validated these measurements against theoretical predictions and thoroughly examined for potential systematic biases, we have found that the impact of source galaxy clustering and reduced shear on the i3PCF is negligible for Stage-III surveys. Furthermore, we have tested the Gaussianity assumption for the likelihood of our data vector and found that while the sampling distribution of the 2PCF can be well approximated by a Gaussian function, the likelihood of the combined 2PCF + i3PCF data vector including filter sizes of and larger can deviate from this assumption. Our SBI pipeline employs masked autoregressive flows to perform neural likelihood estimation and is validated to give statistically accurate posterior estimates. On mock data, we find that including the i3PCF yields a substantial median improvement in the figure of merit for . These findings are consistent with previous works on the i3PCF and demonstrate that our SBI framework can achieve the accuracy and realism needed to analyse the i3PCF in wide-area weak lensing surveys.
28 pages + appendix. 21 figures. Comments are welcome!
References in corpus (66)
- emcee: The MCMC Hammer
- HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
- LSST: from Science Drivers to Reference Design and Anticipated Data Products
- The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
- Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
- The Hyper Suprime-Cam SSP Survey: Overview and Survey Design
- The Dark Energy Survey: more than dark energy - an overview
- Why your model parameter confidences might be too optimistic -- unbiased estimation of the inverse covariance matrix
- Cosmology with cosmic shear observations: a review
- The Shear TEsting Programme 1: Weak lensing analysis of simulated ground-based observations
- Dark energy constraints from cosmic shear power spectra: impact of intrinsic alignments on photometric redshift requirements
- The Kilo-Degree Survey
- Dark Energy Survey Year 3 Results: Cosmology from Cosmic Shear and Robustness to Modeling Uncertainty
- Weak lensing for precision cosmology
- HMcode-2020: Improved modelling of non-linear cosmological power spectra with baryonic feedback
- Galaxy alignments: An overview
- The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology
- Constraints on intrinsic alignment contamination of weak lensing surveys using the MegaZ-LRG sample
- Fast likelihood-free cosmology with neural density estimators and active learning
- Hyper Suprime-Cam Year 3 Results: Cosmology from Cosmic Shear Power Spectra
- A new method to quantify the effects of baryons on the matter power spectrum
- Dark Energy Survey Year 3 Results: Photometric Data Set for Cosmology
- Intrinsic alignments of SDSS-III BOSS LOWZ sample galaxies
- Quantifying baryon effects on the matter power spectrum and the weak lensing shear correlation
- The impact of baryons on the matter power spectrum from the Horizon-AGN cosmological hydrodynamical simulation
- Dark Energy Survey Year 3 Results: Weak Lensing Shape Catalogue
- A non-linear solution to the tension?
- A new approach to observational cosmology using the scattering transform
- The impact of intrinsic alignment on current and future cosmic shear surveys
- Likelihood-free inference with neural compression of DES SV weak lensing map statistics
- KiDS-Legacy: Cosmological constraints from cosmic shear with the complete Kilo-Degree Survey
- Nuisance hardened data compression for fast likelihood-free inference
- Position-dependent power spectrum of the large-scale structure: a novel method to measure the squeezed-limit bispectrum
- Photometric Redshifts for Next-Generation Surveys
- Dark Energy Survey Year 3 Results: Covariance Modelling and its Impact on Parameter Estimation and Quality of Fit
- Cosmological parameters from combined second- and third-order aperture mass statistics of cosmic shear
- Emulation of baryonic effects on the matter power spectrum and constraints from galaxy cluster data
- Performance of internal Covariance Estimators for Cosmic Shear Correlation Functions
- Massive data compression for parameter-dependent covariance matrices
- Euclid Preparation. XXVIII. Forecasts for ten different higher-order weak lensing statistics
- Responses in Large-Scale Structure
- A Full CDM Analysis of KiDS-1000 Weak Lensing Maps using Deep Learning
- The fifth data release of the Kilo Degree Survey: Multi-epoch optical/NIR imaging covering wide and legacy-calibration fields
- The integrated 3-point correlation function of cosmic shear
- Accurate Analytic Model for the Weak Lensing Convergence One-Point Probability Distribution Function and its Auto-Covariance
- CosmoGridV1: a simulated CDM theory prediction for map-level cosmological inference
- KiDS-1000 cosmology: Combined second- and third-order shear statistics
- KiDS-SBI: Simulation-based inference analysis of KiDS-1000 cosmic shear
- Fast Generation of Covariance Matrices for Weak Lensing
- It takes two to know one: Computing accurate one-point PDF covariances from effective two-point PDF models
- Fast Lightcones for Combined Cosmological Probes
- Cosmological constraints from weak lensing scattering transform using HSC Y1 data
- Cosmology from the integrated shear 3-point correlation function: simulated likelihood analyses with machine-learning emulators
- A roadmap to cosmological parameter analysis with third-order shear statistics III: Efficient estimation of third-order shear correlation functions and an application to the KiDS-1000 data
- Map-level baryonification: Efficient modelling of higher-order correlations in the weak lensing and thermal Sunyaev-Zeldovich fields
- Cosmological feedback from a halo assembly perspective
- Unleashing cosmic shear information with the tomographic weak lensing PDF
- Euclid and KiDS-1000: Quantifying the impact of source-lens clustering on cosmic shear analyses
- Dark Energy Survey Year 3 Results: Cosmological constraints from second and third-order shear statistics
- Cosmology with second and third-order shear statistics for the Dark Energy Survey: Methods and simulated analysis
- The DECADE cosmic shear project I: A new weak lensing shape catalog of 107 million galaxies
- Map-level baryonification: unified treatment of weak lensing two-point and higher-order statistics
- Cosmological Inference with Cosmic Voids and Neural Network Emulators
- Position-Dependent Correlation Function of Weak Lensing Convergence
- Simulation-based inference has its own Dodelson-Schneider effect (but it knows that it does)
- Bye binormal: analysing the joint PDF of galaxy density and weak lensing convergence