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The VST Optical Imaging of the CDFS and ES1 Fields (VOICE) Survey is proposed to obtain deep optical $ugri$ imaging of the CDFS and ES1 fields using the VLT Survey Telescope (VST). At present, the observations for the CDFS field have been…

We study how joint shear and magnification measurements improve the statistical precision of weak lensing mass calibration experiments, relative to standard shear-only analysis. For our magnification measurements, we consider not only the…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-30 Eduardo Rozo , Fabian Schmidt

We present the development of a data-driven, AI-based model of the Point Spread Function (PSF) that achieves higher accuracy than the current state-of-the-art approach, "PSF in the Full Field-of-View'' (PIFF). PIFF is widely used in leading…

Instrumentation and Methods for Astrophysics · Physics 2026-02-18 Dayana Andrea Henao Arbeláez , Pierre-François Léget , Andrés Alejandro Plazas Malagón

Increasingly large areas in cosmic shear surveys lead to a reduction of statistical errors, necessitating to control systematic errors increasingly better. One of these systematic effects was initially studied by Hartlap et al. in 2011,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Eray Genc , Peter Schneider , Sandra Unruh , Tim Schrabback

We investigate the extent to which cosmic size magnification may be used to com- plement cosmic shear in weak gravitational lensing surveys, with a view to obtaining high-precision estimates of cosmological parameters. Using simulated…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Biuse Casaponsa , Alan F. Heavens , Tom D. Kitching , Lance Miller , Rita Belén Barreiro , Enrique Martínez-Gonzalez

A long standing problem in weak lensing is about how to construct cosmic shear estimators from galaxy images. Conventional methods average over a single quantity per galaxy to estimate each shear component. We show that any such shear…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jun Zhang , Eiichiro Komatsu

We investigate the weak lensing shear due to dark matter galaxy halos whose mass distributions, as projected on the sky, are nearly elliptical. The shear pattern due to these halos is anisotropic about the lens centers and we quantify the…

Astrophysics · Physics 2007-05-23 T. G. Brainerd , C. O. Wright

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

We present the results of weak gravitational lensing statistics in four different cosmological $N$-body simulations. The data has been generated using an algorithm for the three-dimensional shear, which makes use of a variable softening…

Astrophysics · Physics 2009-10-31 Andrew J. Barber , Peter A. Thomas , H. M. P. Couchman , C. J. Fluke

We generalize ERA method of PSF correction for more realistic situations. The method re-smears the observed galaxy image(galaxy image smeared by PSF) and PSF image by an appropriate function called Re-Smearing Function(RSF) to make new…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Yuki Okura , Toshifumi Futamase

Given a galaxy image, one cannot simply measure its flexion. An image's spin one and three shape properties, typically associated with F- and G-flexion, are actually complicated functions of the galaxy's intrinsic shape and the telescope's…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-26 Rebecca Sobel Levinson

We report a detection of the coherent distortion of faint galaxies arising from gravitational lensing by foreground structures. This ``cosmic shear'' is potentially the most direct measure of the mass power spectrum, as it is unaffected by…

Astrophysics · Physics 2011-05-05 David Bacon , Alexandre Refregier , Richard Ellis

We develop a methodology to construct low-dimensional predictive models from data sets representing essentially nonlinear (or non-linearizable) dynamical systems with a hyperbolic linear part that are subject to external forcing with…

Dynamical Systems · Mathematics 2022-04-06 Mattia Cenedese , Joar Axås , Bastian Bäuerlein , Kerstin Avila , George Haller

Weak gravitational lensing is one of the most important probes of the nature of dark matter and dark energy. In order to extract cosmological information from next-generation weak lensing surveys (e.g., Euclid, Roman, LSST, and CSST) as…

Here we present a number of improvements to weak lensing 3D power spectrum analysis, 3D cosmic shear, that uses the shape and redshift information of every galaxy to constrain cosmological parameters. We show how photometric redshift…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 T. D. Kitching , A. F. Heavens , L. Miller

Weak gravitational lensing is a powerful probe for constraining cosmological parameters, but its success relies on accurate shear measurements. In this paper, we use image simulations to investigate how a joint analysis of high-resolution…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-22 Shiyang Zhang , Shun-Sheng Li , Henk Hoekstra

Finding strong gravitational lenses in astronomical images allows us to assess cosmological theories and understand the large-scale structure of the universe. Previous works on lens detection do not quantify uncertainties in lens parameter…

Instrumentation and Methods for Astrophysics · Physics 2022-11-22 Yash Patel , Jeffrey Regier

We introduce deep-field metacalibration, a new technique that reduces the pixel noise in metacalibration estimators of weak lensing shear signals by using a deeper imaging survey for calibration. In standard metacalibration, when estimating…

Instrumentation and Methods for Astrophysics · Physics 2023-05-19 Zhuoqi Zhang , Matthew R. Becker , Erin S. Sheldon

We implement the Elliptical Gauss-Laguerre (EGL) galaxy-shape measurement method proposed by Bernstein & Jarvis (2002) and quantify the shear recovery accuracy in weak lensing analysis. This method uses a deconvolution fitting scheme to…

Astrophysics · Physics 2008-11-26 Reiko Nakajima , Gary Bernstein

The ratio of the average tangential shear signal of different weak lensing source populations around the same lens galaxies, also known as a shear ratio, provides an important test of lensing systematics and a potential source of…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-01 Ni Emas , Chris Blake , Rossana Ruggeri , Anna Porredon
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