English
Related papers

Related papers: Weak Lensing Mass Reconstruction: Flexion vs Shear

200 papers

Weak gravitational lensing allows one to reconstruct the spatial distribution of the projected mass density across the sky. These "mass maps" provide a powerful tool for studying cosmology as they probe both luminous and dark matter. In…

We investigate the effects of weak gravitational lensing in the standard Cold Dark Matter cosmology, using an algorithm which evaluates the shear in three dimensions. The algorithm has the advantage of variable softening for the particles,…

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

The weak distortions produced by gravitational lensing in the images of background galaxies provide a method to measure directly the distribution of mass in the universe. However this technique requires high precision measurements of the…

Astrophysics · Physics 2009-10-31 Jason Rhodes , Alexandre Refregier , Ed Groth

Weak lensing can be observed through a number of effects on the images of distant galaxies; their shapes are sheared, their sizes and fluxes (magnitudes) are magnified and their positions on the sky are modified by the lensing field. Galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-12 Justin Alsing , Donnacha Kirk , Alan Heavens , Andrew Jaffe

Weak gravitational lensing is normally assumed to have only two principle effects: a magnification of a source and a distortion of the sources shape in the form of a shear. However, further distortions are actually present owing to changes…

General Relativity and Quantum Cosmology · Physics 2015-12-02 Chris Clarkson

The developments summarized with the name ``weak gravitational lensing'' have led to exciting possibilities to study the (statistical properties of the) dark matter distribution in the Universe. Concentrating on those aspects which require…

Astrophysics · Physics 2007-05-23 Peter Schneider , Jean-Paul Kneib

We present the theoretical and analytical bases of optimal techniques to measure weak gravitational shear from images of galaxies. We first characterize the geometric space of shears and ellipticity, then use this geometric interpretation…

Astrophysics · Physics 2009-11-06 G. M. Bernstein , M. Jarvis

Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them. The non-linear evolution of large scale structure produces a non-Gaussian signal which is…

Astrophysics · Physics 2009-10-31 Asantha Cooray , Wayne Hu

Gravitational Lensing is a UNIQUE tool to constrain the mass distribution of collapsed structures, this is particularly true for galaxies, either on a case by case basis using multiple images of background sources (such as quasars), or…

Astrophysics · Physics 2017-08-23 Jean-Paul Kneib

Weak gravitational lensing flexions are a kind of weak lensing distortion which are defined as the spin 1 and spin 3 combinations of the third order derivatives of gravitational lensing potential. Since the shear has spin 2 combination of…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-17 Yuki Okura , Toshifumi Futamase

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 describe a new method for measuring galaxy magnification due to weak gravitational lensing. Our method makes use of a tight scaling relation between galaxy properties that are modified by gravitational lensing, such as apparent size, and…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-07 Eric M. Huff , Genevieve J. Graves

The distortion of images of faint background galaxies by (weak) gravitational lensing can be used to measure the mass distribution of the deflector. The image distortions can be used to define a weighted mean of the mass inside a circular…

Astrophysics · Physics 2015-06-24 Peter Schneider

Weak gravitational lensing is rapidly becoming one of the principal probes of dark matter and dark energy in the universe. In this brief review we outline how weak lensing helps determine the structure of dark matter halos, measure the…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-25 Dragan Huterer

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

In this paper, we develop a new gravitational lensing inversion technique. While traditional approaches assume that the lensing field varies little across a galaxy image, we note that this variation in the field can give rise to a…

Astrophysics · Physics 2009-11-10 David M. Goldberg , David J. Bacon

This article reviews recent advances in the application of machine learning to weak-lensing cosmology. Weak gravitational lensing provides a unique and powerful probe of the total matter distribution in the Universe, independent of its…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-14 Masato Shirasaki

Motivated by the limitations encountered with the commonly used direct reconstruction techniques of producing mass maps, we have developed a multi-resolution maximum-likelihood reconstruction method for producing two dimensional mass maps…

Astrophysics · Physics 2009-11-13 H. Khiabanian , I. P. Dell'Antonio

The weak gravitational lensing distortion of distant galaxy images (defined as sources) probes the projected large-scale matter distribution in the Universe. To improve quality in the 3D mass mapping using 3D-lensing, we combine the lensing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Patrick Simon

The available probes of the large scale structure in the Universe have distinct properties: galaxies are a high resolution but biased tracer of mass, while weak lensing avoids such biases but, due to low signal-to-noise ratio, has poor…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-28 Rafal M. Szepietowski , David J. Bacon , Joerg P. Dietrich , Michael Busha , Risa Wechsler , Peter Melchior