Related papers: Backscattering: an overlooked effect of General Re…
The influence of intergalactic magnetic fields on the strong gravitational lensing of blazar secondary gamma radiation is discussed. Currently, two cases of strong gravitational lensing of blazar gamma-radiation are known, where radiation…
It is shown without making use of Lorentz transformation that there exists a phenomenon of relativistic zero-frequency shift in Doppler effect for a plane wave in free space, observed in two inertial frames of relative motion, and the zero…
We discuss the conditions under which plane electromagnetic and gravitational waves can be amplified by a rotating black hole due to superradiant scattering. We show, in particular, that amplification can occur for low-frequency waves with…
General relativity explains gravitational radiation from binary black hole or neutron star mergers, from core-collapse supernovae and even from the inflation period in cosmology. These waves exhibit a unique effect called memory or…
This paper revisits the controversy concerning whether gravitational lensing effects make a significant difference to estimation of distance to the Cosmic Microwave Background last scattering surface in cosmology. A recent paper by Kaiser…
The paper gives an introduction to the gravitational radiation theory of isolated sources and to the propagation properties of light rays in radiative gravitational fields. It presents a theoretical study of the generation, propagation,…
When modelling the ionisation of gas in the intergalactic medium after reionisation, it is standard practice to assume a uniform radiation background. This assumption is not always appropriate; models with radiative transfer show that…
The observed accelerating universe indicates the presence of Dark Energy which is probably interpreted in terms of an extremely light gravitational scalar field. We suggest a way to probe this scalar field which contributes to optical…
As light propagates along a waveguide, a fraction of the field can be reflected by Rayleigh scatterers. In high-quality-factor whispering-gallery-mode microresonators, this intrinsic backscattering is primarily caused by either surface or…
Gravitational waves in the linear approximation propagate in the Schwarzschild spacetime similarly as electromagnetic waves. A fraction of the radiation scatters off the curvature of the geometry. The energy of the backscattered part of an…
Astrophysical sources emit gravitational waves in a large variety of processes occurred since the beginning of star and galaxy formation. These waves permeate our high redshift Universe, and form a background which is the result of the…
We study the coupling of massive scalar fields to matter in orbit around rotating black holes. It is generally expected that orbiting bodies will lose energy in gravitational waves, slowly inspiralling into the black hole. Instead, we show…
An improved formula for the timing of binary pulsars that accounts for the relativistic deflection of light in the gravitational field of the pulsar's companion is presented, and the measurability of this effect together with its variance…
The scattering of pointlike particles at very large center of mass energies and fixed low momentum transfers, occurring due to both their electromagnetic and gravitational interactions is re-examined in the particular case when one of the…
A massive astrophysical object deforms a local distribution of dark matter, resulting in a local overdensity of dark matter. This phenomenon is often referred to as gravitational focusing. In the solar system, the gravitational focusing due…
It was suggested earlier that the gravitational redshift formula can be invalid when the effect of the backscattering is strong. It is demonstrated here numerically, for an exemplary electromagnetic pulse that is: i) initially located very…
The direct detection of gravitational waves crowns decades of efforts in the modelling of sources and of increasing detectors' sensitivity. With future third-generation Earth-based detectors or space-based observatories, gravitational-wave…
The conversion of gravitational to electromagnetic waves in the presence of background magnetic fields is known as the inverse Gertsenshtein effect, analogous to the Primakoff effect for axions. Rephrasing this conversion as a classical…
The gravitational back-reaction is calculated for the conformally invariant scalar field within a black cosmic string interior with cosmological constant. Using the perturbed metric, the gravitational effects of the quantum field are…
Nature succeeds in accelerating extended and massive objects to relativistic velocities. Jets in Active Galactic Nuclei and in galactic superluminal sources and gamma-ray bursts fireballs have bulk Lorentz factors from a few to several…