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Cosmic shear surveys serve as a powerful tool for mapping the underlying matter density field, including non-visible dark matter. A key challenge in cosmic shear surveys is the accurate reconstruction of lensing convergence ($\kappa$) maps…

Instrumentation and Methods for Astrophysics · Physics 2025-11-27 Yuan Shi , Pengjie Zhang , Furen Deng , Shuren Zhou , Hongbo Cai , Ji Yao , Zeyang Sun

Weak lensing mass-mapping from shear catalogs faces systematic challenges from survey masks and spatially varying noise. To overcome these issues and reconstruct unbiased convergence $\kappa$ maps, we have constructed the AKRA (Accurate…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-23 Yuan Shi , Pengjie Zhang , Zhao Chen , Jian Qin , Li Cui , Furen Deng , Ji Yao

We present KaRMMa 2.0, an updated version of the mass map reconstruction code introduced in Fiedorowicz et al. (2022). KaRMMa is a full-sky Bayesian algorithm for reconstructing weak lensing mass maps from shear data. It forward-models the…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-25 Pier Fiedorowicz , Eduardo Rozo , Supranta S. Boruah

We present a numerical investigation of nonlinear cluster lens reconstruction using weak lensing mass mapping. Recent advances in imaging and shear estimation have pushed reliable reduced shear measurements closer to cluster cores, making…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-23 Yuan Shi , Li Cui

We present KaRMMa, a novel method for performing mass map reconstruction from weak-lensing surveys. We employ a fully Bayesian approach with a physically motivated lognormal prior to sample from the posterior distribution of convergence…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-02 Pier Fiedorowicz , Eduardo Rozo , Supranta S. Boruah , Chihway Chang , Marco Gatti

Weak lensing mass-mapping is a useful tool to access the full distribution of dark matter on the sky, but because of intrinsic galaxy ellipticies and finite fields/missing data, the recovery of dark matter maps constitutes a challenging…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Benjamin Remy , Francois Lanusse , Niall Jeffrey , Jia Liu , Jean-Luc Starck , Ken Osato , Tim Schrabback

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

High precision cosmological distance measurements towards individual objects such as time delay gravitational lenses or type Ia supernovae are affected by weak lensing perturbations by galaxies and groups along the line of sight. In time…

Weak lensing observations measure the shear field and hence the gradient of the dimensionless surface density $\kappa$. We present several new algorithms to recover $\kappa$ {}from shear estimates on a finite region and compare how they…

Astrophysics · Physics 2009-10-28 Gordon Squires , Nick Kaiser

We introduce the skew-spectrum statistic for weak lensing convergence $\kappa$ maps and test it against state-of-the-art high-resolution all-sky numerical simulations. We perform the analysis as a function of source redshift and smoothing…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 D. Munshi , T. Namikawa , T. D. Kitching , J. D. McEwen , F. R. Bouchet

Weak lensing, which is the deflection of light by matter along the line of sight, has proven to be an efficient method for constraining models of structure formation and reveal the nature of dark energy. So far, most weak-lensing studies…

Context: Weak gravitational lensing is a key cosmological probe for current and future large-scale surveys. While power spectra are commonly used for analyses, they fail to capture non-Gaussian information from nonlinear structure…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-17 Vilasini Tinnaneri Sreekanth , Jean-Luc Starck , Sandrine Codis

Weak lensing will play an important role in future cosmological surveys, including e.g. Euclid and SKA. Sufficiently accurate theoretical predictions are important for correctly interpreting these surveys and hence for extracting correct…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-07 Sofie Marie Koksbang , Chris Clarkson

In \citep{Qin+}, we attempted to reconstruct the weak lensing convergence map $\hat{\kappa}$ from cosmic magnification by linearly weighting the DECaLS galaxy overdensities in different magnitude bins of $grz$ photometry bands. The…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Jian Qin , Pengjie Zhang , Yu Yu , Haojie Xu , Ji Yao , Yuan Shi , Huanyuan Shan

We develop an algorithm for the reconstruction of the two-dimensional mass distribution of a gravitational lens from the observable distortion of background galaxies. From the measured reduced shear, the lens mapping is obtained, from which…

Astrophysics · Physics 2009-10-31 Tarun Deep Saini , Somak Raychaudhury

Purpose: To develop a scan-specific model that estimates and corrects k-space errors made when reconstructing accelerated Magnetic Resonance Imaging (MRI) data. Methods: Scan-Specific Artifact Reduction in k-space (SPARK) trains a…

Signal Processing · Electrical Eng. & Systems 2022-04-29 Yamin Arefeen , Onur Beker , Jaejin Cho , Heng Yu , Elfar Adalsteinsson , Berkin Bilgic

We present a concept study on weak lensing map reconstruction through the cosmic magnification effect in galaxy number density distribution. We propose a minimal variance linear estimator to minimize both the dominant systematical and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-16 Xinjuan Yang , Pengjie Zhang

Alternative to weak lensing measurements through cosmic shear, we present a weak lensing convergence $\hat{\kappa}$ map reconstructed through cosmic magnification effect in DECaLS galaxies of the DESI imaging surveys DR9. This is achieved…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-05 Jian Qin , Pengjie Zhang , Haojie Xu , Yu Yu , Ji Yao , Ruijie Ma , Huanyuan Shan

We apply a mass reconstruction technique to simulated large-scale structure gravitational distortion maps, from 2.5' to 10 degree scales, for different cosmological scenarii. The projected mass is reconstructed using a non-parametric least…

Astrophysics · Physics 2007-05-23 L. Van Waerbeke , F. Bernardeau , Y. Mellier
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