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International Astronomical Union Colloquium, 2001 AbstractIn the roughly 20 years of its existence as an observational science, gravitational lensing has established itself as a valuable tool in many astrophysical fields. In the introduction of this review we briefly present the basics of lensing. Then it is shown that the two propagation effects, lensing and scintillation, have a number of properties
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The Scales of Gravitational Lensing [PDF]
Universe, 2016 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 the distribution of the stellar component in the Milky Way, to study dark matter and dark energy on very large ...
DE PAOLIS, Francesco +5 more
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Gravitational lensing by wormholes [PDF]
Physical Review D, 2006 Gravitational lensing by traversable Lorentzian wormholes is a ew possibility which is analyzed here in the strong field limit. Wormhole solutions are considered in the Einstein minimally coupled theory and in the brane world model. The observables in both the theories show significant differences from those arising in the Schwarzschild black hole ...
Alexander V. Zakharov +4 more
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Exploring gravitational lensing [PDF]
European Journal of Physics, 2019 In this article, we discuss the idea of gravitational lensing, from a systematic, historical and didactic point of view. We show how the basic lensing equation together with the concepts of geometrical optics opens a space of implications that can be explored along different dimensions.
Tilman Sauer, Tobias Schütz
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Rotation in gravitational lenses [PDF]
Monthly Notices of the Royal Astronomical Society, 2006 Gravitational lensing deflects light. A single lens deflector can only shear images, but cannot induce rotations. Multiple lens planes can induce rotations. Such rotations can be observed in quadruply imaged sources, and can be used to distinguish between two proposed solutions of the flux anomaly problem: substructures in lensing galaxies vs large ...
Shude Mao, Ue-Li Pen
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GRAVITATIONAL LENSING BY WORMHOLES [PDF]
Modern Physics Letters A, 2008 We have investigated the gravitational lensing by two wormholes, viz., Janis–Newman–Winnicour (JNW) wormhole and Ellis wormhole. The deflection angles in the strong field limit are calculated and various lens parameters of two wormholes are compared. It is shown that the JNW wormhole exhibits the relativistic images, while the Ellis wormhole does not ...
Tushar Kanti Dey, Surajit Sen
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Degeneracy in exotic gravitational lensing [PDF]
, 2002 We present three different theoretically foreseen, but unusual, astrophysical situations where the gravitational lens equation ends up being the same, thus producing a degeneracy problem.
Cooray A. +9 more
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Highlights of Astronomy, 1992 AbstractAtmospheric lensing effects deform our view of distant objects; similarly, without any doubt, gravitational lensing perturbs our view of the distant Universe and affects our physical understanding of various classes of extragalactic objects.
Sjur Refsdal, Jean Surdej
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Modulation of a Chirp Gravitational Wave from a Compact Binary due to Gravitational Lensing [PDF]
, 2005 A possible wave effect in the gravitational lensing phenomenon is discussed. We consider the interference of two coherent gravitational waves of slightly different frequencies from a compact binary, due to the gravitational lensing by a galaxy halo. This
B. F. Schutz +4 more
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Probing the dark matter issue in f(R)-gravity via gravitational lensing [PDF]
, 2011 For a general class of analytic f(R)-gravity theories, we discuss the weak field limit in view of gravitational lensing. Though an additional Yukawa term in the gravitational potential modifies dynamics with respect to the standard Newtonian limit of ...
A. De Felice +62 more
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