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In this work are reviewed several aspects of gravitational lensing produced by astrophysical bodies that strongly curve the spacetime in their vicinity. When an object with a photon sphere (e.g. a black hole) is interposed between a source…

General Relativity and Quantum Cosmology · Physics 2014-09-15 Ernesto F. Eiroa

Gravitational lensing magnification modifies the observed spatial distribution of galaxies and can severely bias cosmological probes of large-scale structure if not accurately modelled. Standard approaches to modelling this magnification…

While the Hubble constant can be derived from observable time delays between images of lensed quasars, the result is often highly sensitive to assumptions and systematic uncertainties in the lensing model. Unlike most previous authors we…

Astrophysics · Physics 2009-10-31 HongSheng Zhao , Danny Pronk

We introduce a novel method for weak-lensing measurements, which is based on a mathematically exact deconvolution of the moments of the apparent brightness distribution of galaxies from the telescope's PSF. No assumptions on the shape of…

Instrumentation and Methods for Astrophysics · Physics 2012-04-24 Peter Melchior , Massimo Viola , Björn Malte Schäfer , Matthias Bartelmann

The observables in a strong gravitational lens are usually just the image positions and sometimes the flux ratios. We develop a new and simple algorithm which allows a set of models to be fitted exactly to the observations. Taking our cue…

Astrophysics · Physics 2008-11-26 N. W. Evans , H. J. Witt

Dedicated 'Stage IV' observatories will soon observe the entire extragalactic sky, to measure the 'cosmic shear' distortion of galaxy shapes by weak gravitational lensing. To measure the apparent shapes of those galaxies, we present an…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-08 Xiangchong Li , Yin Li , Richard Massey

Massive structures, such as galaxies, act as strong gravitational lenses on background sources. When the background source is a quasar, several lensed images are seen, as magnified or de-magnified versions of the same object. The detailed…

Astrophysics · Physics 2007-05-23 F. Courbin , P. Saha , P. L. Schechter

Supermassive black hole binary systems (SMBHB) are standard sirens -- the gravitational wave analogue of standard candles -- and if discovered by gravitational wave detectors, they could be used as precise distance indicators.…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-08 Charles Shapiro , David Bacon , Martin Hendry , Ben Hoyle

We introduce a novel approach for detecting gravitational waves through their influence on the shape of resolved astronomical objects. This method, complementary to pulsar timing arrays and astrometric techniques, explores the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-22 Giorgio Mentasti , Carlo R. Contaldi

Classification of galactic morphologies is a crucial task in galactic astronomy, and identifying fine structures of galaxies (e.g., spiral arms, bars, and clumps) is an essential ingredient in such a classification task. However, seeing…

Instrumentation and Methods for Astrophysics · Physics 2021-03-30 Fang Kai Gan , Kenji Bekki , Abdolhosein Hashemizadeh

Cosmic shear is the distortion of images of distant galaxies due to weak gravitational lensing by the large-scale structure in the Universe. Such images are coherently deformed by the tidal field of matter inhomogeneities along the line of…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-22 Martin Kilbinger

The ImageNet Large Scale Visual Recognition Challenge is a benchmark in object category classification and detection on hundreds of object categories and millions of images. The challenge has been run annually from 2010 to present,…

Computer Vision and Pattern Recognition · Computer Science 2015-02-02 Olga Russakovsky , Jia Deng , Hao Su , Jonathan Krause , Sanjeev Satheesh , Sean Ma , Zhiheng Huang , Andrej Karpathy , Aditya Khosla , Michael Bernstein , Alexander C. Berg , Li Fei-Fei

We devise a test of nonlinear departures from general relativity (GR) using time delays in strong gravitational lenses. We use a phenomenological model of gravitational screening as a step discontinuity in the measure of curvature per unit…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 Dhrubo Jyoti , Julian B. Munoz , Robert R. Caldwell , Marc Kamionkowski

After exactly a century since the formulation of the general theory of relativity, the phenomenon of gravitational lensing is still an extremely powerful method for investigating in astrophysics and cosmology. Indeed, it is adopted to study…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-25 Francesco De Paolis , Mosè Giordano , Gabriele Ingrosso , Luigi Manni , Achille Nucita , Francesco Strafella

Upcoming deep optical surveys, such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), will scan the sky to unprecedented depths, detecting billions of galaxies. However, this amount of detections will lead to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-04 Manon Ramel , Cyrille Doux , Marine Kuna

In a strong gravitational lensing system, the distorted light from a source is analysed to infer the properties of the lens. However, light emitted by the lens itself can contaminate the image of the source, introducing systematic errors in…

We derive expressions, in terms of "polar shapelets", for the image distortion operations associated with weak gravitational lensing. Shear causes galaxy shapes to become elongated, and is sensitive to the second derivative of the projected…

Astrophysics · Physics 2008-11-26 Richard Massey , Barnaby Rowe , Alexandre Refregier , David J. Bacon , Joel Berge

Gravitational waves, like light, can be gravitationally lensed by massive astrophysical objects such as galaxies and galaxy clusters. Strong gravitational-wave lensing, forecasted at a reasonable rate in ground-based gravitational-wave…

General Relativity and Quantum Cosmology · Physics 2021-08-18 Justin Janquart , Otto A. Hannuksela , Haris K. , Chris Van Den Broeck

Gravitational waves (GW) from chirping binary black holes (BBHs) provide unique opportunities to test general relativity (GR) in the strong-field regime. However, testing GR can be challenging when incomplete physical modeling of the…

General Relativity and Quantum Cosmology · Physics 2025-07-09 Anuj Mishra , N. V. Krishnendu , Apratim Ganguly

It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$.…

Astrophysics · Physics 2008-02-03 Philippe Jetzer
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