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We perform a blinded cosmology analysis with cosmic shear two-point correlation functions (2PCFs) measured from more than 25 million galaxies in the Hyper Suprime-Cam three-year shear catalog in four tomographic redshift bins ranging from…

Precise cosmological inference from next-generation weak lensing surveys requires extracting non-Gaussian information beyond standard two-point statistics. We present a hybrid machine-learning (ML) framework that integrates field-level…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-19 Jiacheng Ding , Chen Su , Ji Yao , Le Zhang , Huanyuan Shan

This article details the computation of the two-point correlators of the convergence, $E$- and $B$-modes of the cosmic shear induced by the weak-lensing by large scale structure assuming that the background spacetime is spatially…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-13 Cyril Pitrou , Thiago S. Pereira , Jean-Philippe Uzan

Weak lensing peak counts are a powerful statistical tool for constraining cosmological parameters. So far, this method has been applied only to surveys with relatively small areas, up to several hundred square degrees. As future surveys…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-01 Janis Fluri , Tomasz Kacprzak , Raphael Sgier , Alexandre Réfrégier , Adam Amara

Designing a covariance function that represents the underlying correlation is a crucial step in modeling complex natural systems, such as climate models. Geospatial datasets at a global scale usually suffer from non-stationarity and…

Machine Learning · Statistics 2015-07-10 Chintan A. Dalal , Vladimir Pavlovic , Robert E. Kopp

We calculate the systematic errors in the weak gravitational lensing power spectrum which would be caused by spatially varying calibration (i.e. multiplicative) errors, such as might arise from uncorrected seeing or extinction variations.…

Astrophysics · Physics 2009-11-13 Jacek Guzik , Gary Bernstein

We use weak lensing data from the Hubble Space Telescope COSMOS survey to measure the second- and third-moments of the cosmic shear field, estimated from about 450,000 galaxies with average redshift <z> ~ 1.3. We measure two- and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Elisabetta Semboloni , Tim Schrabback , Ludovic van Waerbeke , Sanaz Vafaei , Jan Hartlap , Stefan Hilbert

Previous work on three-point statistics of cosmic shear has mainly concentrated on the convergence, or on aperture measures of the shear. However, as has become clear recently for the two-point statistics of cosmic shear, the basic quantity…

Astrophysics · Physics 2009-11-07 Peter Schneider , Marco Lombardi

Accurate reconstruction of the spatial distributions of the Point Spread Function (PSF) is crucial for high precision cosmic shear measurements. Nevertheless, current methods are not good at recovering the PSF fluctuations of high spatial…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-12 Tianhuan Lu , Jun Zhang , Fuyu Dong , Yingke Li , Dezi Liu , Liping Fu , Guoliang Li , Zuhui Fan

The accurate computation of the covariance matrix of fitted model parameters is a somewhat neglected task in Statistics. Algorithms are given for computing accurate covariance matrices derived from computing the Hessian matrix by numerical…

Computation · Statistics 2021-05-12 Rose Baker

The interpretation of cosmological observables requires the use of increasingly sophisticated theoretical models. Since these models are becoming computationally very expensive and display non-trivial uncertainties, the use of standard…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Marcos Pellejero-Ibañez , Raul E. Angulo , Giovanni Aricó , Matteo Zennaro , Sergio Contreras , Jens Stücker

The systematic magnification of background sources by the weak gravitational-lensing effects of foreground matter, also called cosmic magnification, is becoming an efficient tool both for measuring cosmological parameters and for exploring…

Astrophysics · Physics 2015-06-24 Brice Menard , Takashi Hamana , Matthias Bartelmann , Naoki Yoshida

We present a novel method for reconstructing weak lensing mass or convergence maps as a probe to study non-Gaussianities in the cosmic density field. While previous surveys have relied on a flat-sky approximation, the forthcoming stage IV…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-03 Vanshika Kansal

In this study, we investigate the potential of mark-weighted angular correlation functions (MACFs), which integrate $\beta$-cosmic-web classification with angular correlation function analysis to improve cosmological constraints. Using SDSS…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Fenfen Yin , Liang Xiao , Wenying Du , Zhujun Jiang , Zhiwei Min , Jaime Forero-Romero , Jiacheng Ding , Le Zhang , Xiao-Dong Li

We study the statistics of weak lensing convergence peaks, such as their abundance and two-point correlation function (2PCF), for a wide range of cosmological parameters $\Omega_m$ and $\sigma_8$ within the standard $\Lambda$CDM paradigm,…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-08 Christopher T. Davies , Marius Cautun , Baojiu Li

Peak counts have been shown to be an excellent tool to extract the non-Gaussian part of the weak lensing signal. Recently, we developped a fast stochastic forward model to predict weak-lensing peak counts. Our model is able to reconstruct…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-16 Chieh-An Lin , Martin Kilbinger

The next generation of weak gravitational lensing surveys has the potential to place stringent constraints on cosmological parameters. However, their analysis is limited by systematics such as the intrinsic alignments of galaxies, which…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Max E. Lee , Zoltán Haiman , Shivam Pandey , Shy Genel

We present a framework to compute non-Gaussian likelihoods for two-point correlation functions. The non-Gaussianity is most pronounced on large scales that will be well-measured by stage-IV weak-lensing surveys. We show how such a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-09 Veronika Oehl , Tilman Tröster

Weak lensing convergence can be used directly to map and probe the dark mass distribution in the universe. Building on earlier studies, we recall how the statistics of the convergence field are related to the statistics of the underlying…

Astrophysics · Physics 2009-11-07 Andrew J. Barber , Dipak Munshi , Patrick Valageas

The disconnected part of the power spectrum covariance matrix (also known as the "Gaussian" covariance) is the dominant contribution on large scales for galaxy clustering and weak lensing datasets. The presence of a complicated sky mask…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-02 Carlos García-García , David Alonso , Emilio Bellini