English
Related papers

Related papers: A Note on the Overall Magnification of a Gravitati…

200 papers

We discuss the classic theorem according to which a gravitational lens always produces a total magnification greater than unity. This theorem seems to contradict the conservation of total flux from a lensed source. The standard solution to…

Astrophysics · Physics 2009-06-23 O. Wucknitz

To determine the magnification of an extended source caused by gravitational lensing one has to perform a two-dimensional integral over point-source magnifications in general. Since the point-source magnification jumps to an infinite value…

Astrophysics · Physics 2011-05-23 M. Dominik

We study approximate solutions of the gravitational lens equation and corresponding lens magnification factor near the critical point. This consideration is based on the Taylor expansion of the lens potential in powers of coordinates and an…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-01 A. N. Alexandrov , S. M. Koval , V. I. Zhdanov

In this brief communication a new method is outlined for modelling magnification patterns on an observer's plane using a first order approximation to the null geodesic path equations for a point mass lens. For each ray emitted from a…

Instrumentation and Methods for Astrophysics · Physics 2017-02-08 S. J. Walters , L. K. Forbes

We investigate the finite source size effect in the context of the wave optics in the gravitational lensing. The magnification of an extended source is presented in an analytic manner for the singular isothermal sphere lens model as well as…

Astrophysics · Physics 2009-11-11 Norihito Matsunaga , Kazuhiro Yamamoto

We investigate imaging point sources with a monopole gravitational lens, such as the Solar Gravitational Lens in the geometric optics limit. We compute the light amplification of the lens used in conjunction with a telescope featuring a…

Instrumentation and Methods for Astrophysics · Physics 2023-11-08 Viktor T. Toth

We prove a gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is mu =1+pi(2R_E^2-R_L^2)/A, where A is the area of the source and R_E and R_L are the Einstein radius and size of…

Astrophysics · Physics 2009-11-07 Eric Agol

If an extended source, such as a galaxy, is gravitationally lensed by a massive object in the foreground, the lensing distorts the observed image. It is straightforward to simulate what the observed image would be for a particular lens and…

Astrophysics · Physics 2009-11-13 Brendon J. Brewer , Geraint F. Lewis

We study a class of gravitational lensing systems consisting of an inclined ring/belt, with and without an added point mass at the centre. We show that a common feature of such systems are so-called "pseudo-caustics", across which the…

Earth and Planetary Astrophysics · Physics 2016-12-21 Ethan Lake , Zheng Zheng

We revisit the gravitational lensing phenomenon using a new visualization technique. It consists in projecting the observers sky into the source plane, what gives rise to a folded and stretched surface. This provides a clear graphical tool…

Astrophysics · Physics 2016-12-21 Silvia Mollerach , Esteban Roulet

We show that the gravitational magnification factor averaged over all configurations of lenses in a locally inhomogeneous universe satisfy a second order differential equation with redshift $z$ by taking the continuous limit of multi-plane…

Astrophysics · Physics 2007-05-23 Hiroshi Yoshida , Kouji Nakamura , Minoru Omote

The computation of the magnification of a finite source by an arbitrary gravitational lens can be reduced from a two-dimensional to a one-dimensional integral using a generalization of Stoke's theorem. For a large source lensed by a…

Astrophysics · Physics 2007-05-23 Andrew Gould , Cedric Gaucherel

We have worked out simple analytical formulae that accurately approximate the relationship between the position of the source with respect to the lens center and the amplification of the images, hence the lens cross section, for realistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Lapi , M. Negrello , J. Gonzalez-Nuevo , Z. -Y. Cai , G. De Zotti , L. Danese

The mathematical theory of gravitational lensing has revealed many generic and global properties. Beginning with multiple imaging, we review Morse-theoretic image counting formulas and lower bound results, and complex-algebraic upper bounds…

Astrophysics of Galaxies · Physics 2014-11-20 A. O. Petters , M. C. Werner

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

Gravitational lensing is the phenomenon arising when light rays are deflected by the mass between the source and the observer. Largely magnified and highly distorted images of background galaxies are formed by these angular deflections if…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Atınç Çağan Şengül

In gravitational lensing, the magnification effect changes the luminosity and size of a background galaxy. If the image sizes are not small compared to the scale over which the magnification and shear vary, higher-order distortions occur…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Xinzhong Er

This is a general work on gravitational lensing. We present new expressions for the optical scalars and the deflection angle in terms of the energy-momentum tensor components of matter distributions. Our work generalizes standard references…

General Relativity and Quantum Cosmology · Physics 2011-05-12 Emanuel Gallo , Osvaldo M. Moreschi

We show how our theory of large-scale gravitational quantization explains the large angle gravitational lensing by galaxies without requiring "dark matter". A galaxy is treated as a collective system of billions of stars in each…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Franklin Potter , Howard G. Preston

We offer a concise and direct way to derive the bending angle of light (i.e. as generally called, gravitational lensing), while light grazes a star, through the approach suggested earlier by the first author, which is fundamentally based on…

General Physics · Physics 2014-01-15 Tolga Yarman , Alexander Kholmetskii , Metin Arik
‹ Prev 1 2 3 10 Next ›