Related papers: Gravitational Lensing and Gravitomagnetic Time Del…
This thesis contributes to the field of gravitational lensing (GL) and observational cosmology. We discuss the use of gravitational lensing as a tool in search of exotic objects in the Universe. In the next chapter the concordance of an…
The gravitational lensing of a relativistic fireball can produce the time delayed multiple images with quite different spectra and temporal patterns in contrast with a nonrelativistic source and hence can imitate the source recurrence. In…
When gravitational waves propagate near massive objects, their paths curve resulting in gravitational lensing, which is expected to be a promising new instrument in astrophysics. If the time delay between different paths is comparable with…
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.…
When gravitational waves travel from their source to an observer, they interact with matter structures along their path, causing distinct deformations in their waveforms. In this study we introduce a novel theoretical framework for wave…
Listening to echoes has long been a way to estimate distances, a technique whose backbone is the time delay. The gravitational field also creates a time delay, called Shapiro time delay, that helps us extract some information from the field…
(abridged) Gravitationally lensed quasars can be used as powerful cosmological and astrophysical probes. We can (i) infer the Hubble constant based on the time-delay technique, (ii) unveil substructures along the l.o.s. toward distant…
I suggest that measurements of intensity fluctuations caused by classical wave interactions can be used to find unresolved gravitational lenses and determine time delays of essentially arbitrary length among the images formed by a…
0957+561 is the first gravitational lens system to be discovered and first for which a time delay was measured. Because the system is unusually rich in observables such as image positions, fluxes, VLBI structure, and polarization it has…
Gravitational lensing occurs as the path of light from distant celestial bodies is distorted due to gravitational attraction by other celestial bodies, whose mass is partly invisible, being so-called dark matter. When observed through a…
Gravitational lensing and black hole shadows are one of the strongest observational evidences to prove the existence of black holes in the universe. The gravitational lensing arises due to the deflection of light by the gravitational field…
Light undergoes perturbation as gravitational waves pass by. This is shown by solving Maxwell's equations in a spacetime with gravitational waves; a solution exhibits a perturbation due to gravitational waves. We determine the perturbation…
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…
We have analysed archival VLA 8.4-GHz monitoring data of the gravitational lens system JVAS B1030+074 with the goal of determining the time delay between the two lensed images via the polarization variability. In contrast to the previously…
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 $10^{-6} < M/M_{\odot} < 10^{-1}$.…
Gravitationally lensed Type Ia supernovae are an emerging probe with great potential for constraining dark energy, spatial curvature, and the Hubble constant. The multiple images and their time delayed and magnified fluxes may be…
Strong gravitational lens systems with measured time delays between the multiple images provide a method for measuring the "time-delay distance" to the lens, and thus the Hubble constant. We present a Bayesian analysis of the strong…
The long-standing problem of whether the cosmological constant affects directly the deflection of light caused by a gravitational lens is reconsidered. We use a new approach based on the Hawking quasilocal mass of a sphere grazed by light…
The contribution of the cosmological constant to the deflection angle and the time delays are derived from the integration of the gravitational potential as well as from Fermat's Principle. The findings are in agreement with recent results…
We study gravitational lensing by clusters of galaxies in the context of the generic class of unconventional gravity theories of the scalar--tensor type. For positive energy scalar fields with any dynamics, the bending of light by a weakly…