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Within the context of upcoming full-sky lensing surveys, the edge-preserving non- linear algorithm Aski is presented. Using the framework of Maximum A Posteriori inversion, it aims at recovering the full-sky convergence map from surveys…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. Pichon , E. Thiebaut , S. Prunet , K. Benabed , S. Colombi , T. Sousbie , R. Teyssier

A matrix algorithm runs superfast (aka at sublinear cost) if it involves much fewer flops and memory cells than an input matrix has entries. Big Data are frequently represented by matrices of immense sizes that cannot be handled directly…

Numerical Analysis · Mathematics 2025-11-11 Qi Luan , Victor Y. Pan

We present a new method for constructing three-dimensional mass maps from gravitational lensing shear data. We solve the lensing inversion problem using truncation of singular values (within the context of generalized least squares…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Jake VanderPlas , Andrew Connolly , Bhuvnesh Jain , Mike Jarvis

We develop the maximum-entropy weak shear mass reconstruction method presented in earlier papers by taking each background galaxy image shape as an independent estimator of the reduced shear field and incorporating an intrinsic smoothness…

Astrophysics · Physics 2009-11-07 P. J. Marshall , M. P. Hobson , S. F. Gull , S. L. Bridle

Current and upcoming wide-field, ground-based, broad-band imaging surveys promise to address a wide range of outstanding problems in galaxy formation and cosmology. Several such uses of ground-based data, especially weak gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Rachel Mandelbaum , Christopher M. Hirata , Alexie Leauthaud , Richard J. Massey , Jason Rhodes

We investigate the use of estimators of weak lensing power spectra based on a flat-sky implementation of the Pseudo-Cl (PCl) technique, where the masked shear field is transformed without regard for masked regions of sky. This masking mixes…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-11 Marika Asgari , Andy Taylor , Benjamin Joachimi , Thomas D. Kitching

We describe a weak lensing view of the downsizing of star forming galaxies based on cross correlating a weak lensing ($\kappa$) map with a predicted map constructed from a redshift survey. Moderately deep and high resolution images with…

Data processing has to deal with many practical difficulties. Data is often corrupted by artifacts or noise and acquiring data can be expensive and difficult. Thus, the given data is often incomplete and inaccurate. To overcome these…

Numerical Analysis · Mathematics 2022-11-18 Florian Bossmann , Jianwei Ma

Accurate predictions of weak lensing observables are essential for understanding the large-scale structure of the Universe and probing the nature of gravity. In this work, we present a lightcone implementation to generate maps of the weak…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-28 Sophie Hoyland , Hans A. Winther , Daniela Saadeh , Kazuya Koyama , Albert Izard

In this work, we propose an improved approach to reconstruct the three-dimensional intergalactic medium from observed Lyman-$\alpha$ forest absorption features. We present our new method, the Optimized Reconstruction with Constraints on…

Astrophysics of Galaxies · Physics 2021-08-04 Zihao Li , Benjamin Horowitz , Zheng Cai

We present an efficient implementation of Wiener filtering of real-space linear field and optimal quadratic estimator of its power spectrum Band-powers. We first recast the field reconstruction into an optimization problem, which we solve…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-16 Benjamin Horowitz , Uros Seljak , Grigor Aslanyan

In order to reach the required performance of Stage-III and IV weak lensing surveys, cosmic shear measurements have to rely on external simulations to calibrate residual biases. Over the years, several techniques have been developed to…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 G. Congedo , A. N. Taylor

We explore the utility of Karhunen Loeve (KL) analysis in solving practical problems in the analysis of gravitational shear surveys. Shear catalogs from large-field weak lensing surveys will be subject to many systematic limitations,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jake Vanderplas , Andrew Connolly , Bhuvnesh Jain , Mike Jarvis

Optical weak lensing surveys have become a powerful tool for precision cosmology, but remain subject to systematic effects that can severely bias cosmological parameter estimates if not carefully removed. We discuss the possibility of…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-22 Philip Bull , Ian Harrison , Eric Huff

We present HEALFormer, a transformer-based neural network architecture for weak gravitational lensing mass mapping that reconstructs convergence maps from incomplete and noisy shear observations on the celestial sphere. The model operates…

Instrumentation and Methods for Astrophysics · Physics 2026-03-27 Yihe Wang , Yu Yu

We introduce a novel approach to reconstruct dark matter mass maps from weak gravitational lensing measurements. The cornerstone of the proposed method lies in a new modelling of the matter density field in the Universe as a mixture of two…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 J. -L. Starck , K. E. Themelis , N. Jeffrey , A. Peel , F. Lanusse

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and optical/near-IR bands for mitigating systematic effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Stefano Camera , Ian Harrison , Anna Bonaldi , Michael L. Brown

Most cosmic shear analyses to date have relied on summary statistics (e.g. $\xi_+$ and $\xi_-$). These types of analyses are necessarily sub-optimal, as the use of summary statistics is lossy. In this paper, we forward-model the convergence…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-29 Supranta Sarma Boruah , Eduardo Rozo , Pier Fiedorowicz

Kernel Adaptive Filtering (KAF) are mathematically principled methods which search for a function in a Reproducing Kernel Hilbert Space. While they work well for tasks such as time series prediction and system identification they are…

Machine Learning · Computer Science 2023-12-20 Benjamin Colburn , Jose C. Principe , Luis G. Sanchez Giraldo

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