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Related papers: Gravitational Lensing Accuracy Testing 2010 (GREAT…

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The goal of this paper is to develop a machine learning model to analyze the main gravitational lens and detect dark substructure (subhalos) within simulated images of strongly lensed galaxies. Using the technique of image segmentation, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-27 Bryan Ostdiek , Ana Diaz Rivero , Cora Dvorkin

The wealth of incoming and future cosmological observations will allow us to map out the structure and evolution of the observable universe to an unprecedented level of precision. Among these observations is the weak gravitational lensing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 M. A. Troxel , Mustapha Ishak

In this paper we present results from the Mapping Dark Matter competition that expressed the weak lensing shape measurement task in its simplest form and as a result attracted over 700 submissions in 2 months and a factor of 3 improvement…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-19 T. D. Kitching , J. Rhodes , C. Heymans , R. Massey , Q. Liu , M. Cobzarenco , B. L. Cragin , A. Hassaine , D. Kirkby , E. Jin Lok , D. Margala , J. Moser , M. O'Leary , A. M. Pires , S. Yurgenson

It is known that a relative translational motion between the deflector and the observer affects gravitational lensing. In this paper, a lens equation is obtained to describe such effects on actual lensing observables. Results can be easily…

Astrophysics · Physics 2008-11-26 M. Sereno

Whereas considerable effort has been afforded in understanding the properties of galaxies, a full physical picture, connecting their baryonic and dark-matter content, super-massive black holes, and (metric) theories of gravity, is still…

The time delay between images of strongly gravitationally lensed quasars is an established cosmological probe. Its limitations, however, include uncertainties in the assumed mass distribution of the lens. We re-examine the methodology of a…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-17 Angela L. H. Ng

We present a novel approach to estimate the time delay between light curves of multiple images in a gravitationally lensed system, based on Kernel methods in the context of machine learning. We perform various experiments with artificially…

Astrophysics · Physics 2009-11-11 Juan C. Cuevas-Tello , Peter Tino , Somak Raychaudhury

We present a novel test of general relativity (GR): measuring the geometric component of the time delay due to gravitational lensing. GR predicts that photons and gravitational waves follow the same geodesic paths and thus experience the…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-19 David Rubin , Istvan Szapudi , Benjamin J. Shappee , Gagandeep S. Anand

Measured time delays between the images of a gravitationally lensed source can lead to a determination of the Hubble constant ($H_o$), but only if the lensing mass distribution is well understood. The inability to sufficiently constrain…

Astrophysics · Physics 2007-05-23 D. Rusin

Weak gravitational lensing, the correlated distortion of background galaxy shapes by foreground structures, is a powerful probe of the matter distribution in our universe and allows accurate constraints on the cosmological model. In recent…

The limits to the angular resolution achievable with conventional ground-based telescopes are unchanged over 70 years. Atmospheric turbulence limits image quality to typically ~1 arcsec in practice. We have developed a new concept of…

Instrumentation and Methods for Astrophysics · Physics 2016-08-25 Craig Mackay , Martin Dominik , Iain Steele

Dark matter structures within strong gravitational lens galaxies and along their line of sight leave a gravitational imprint on the multiple images of lensed sources. Strong gravitational lensing provides, therefore, a key test of different…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-22 S. Vegetti , S. Birrer , G. Despali , C. D. Fassnacht , D. Gilman , Y. Hezaveh , L. Perreault Levasseur , J. P. McKean , D. M. Powell , C. M. O'Riordan , G. Vernardos

Gravitational lensing causes background galaxy images to become aligned, and the statistical characteristics of the image alignments can then be used to constrain the power spectrum of mass fluctuations. Analyses of gravitational lensing…

Astrophysics · Physics 2017-08-23 A. F. Heavens

LISA might detect gravitational waves from mergers of massive black hole binaries strongly lensed by intervening galaxies (Sereno et al. 2010). The detection of multiple gravitational lensing events would provide a new tool for cosmography.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 M. Sereno , Ph. Jetzer , A. Sesana , M. Volonteri

Gravitational lensing is the phenomenon where the presence of matter (called a lens) bends the path of light-like trajectories travelling nearby. Similar to the geometric optics limit of electromagnetic waves, gravitational lensing of…

General Relativity and Quantum Cosmology · Physics 2024-08-20 Aniruddha Chakraborty , Suvodip Mukherjee

In this article we review the astrophysical application of gravitational microlensing. After introducing the history of gravitational lensing, we present the key equations and concept of microlensing. The most frequent microlensing events…

Instrumentation and Methods for Astrophysics · Physics 2016-03-21 Sohrab Rahvar

Cosmological gravitational microlensing is a useful technique for understanding the structure of the inner parts of a quasar, especially the accretion disk and the central supermassive black hole. So far, most of the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Georgios Vernardos , Christopher J. Fluke

Previous work generally believes that improving the spatial invariance of convolutional networks is the key to object counting. However, after verifying several mainstream counting networks, we surprisingly found too strict pixel-level…

Computer Vision and Pattern Recognition · Computer Science 2022-08-19 Zhi-Qi Cheng , Qi Dai , Hong Li , JingKuan Song , Xiao Wu , Alexander G. Hauptmann

Weak gravitational lensing is considered to be one of the most powerful tools to study the mass and the mass distribution of galaxy clusters. However, weak lensing mass reconstructions are plagued by the so-called mass-sheet degeneracy--the…

Astrophysics · Physics 2007-05-23 M. Bradac , M. Lombardi , P. Schneider

We analyse deep multi-colour Advanced Camera images of the largest known gravitational lens, A1689. Radial and tangential arcs delineate the critical curves in unprecedented detail and many small counter-images are found near the center of…

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