Related papers: Gravitational birefringence and an exotic formula …
First and second order corrections for the scattering of different types of particles by a weak gravitational field, treated as an external field, are calculated. These computations indicate a violation of the Equivalence Principle: to…
Peculiar velocities are a precious tool to study the large-scale distribution of matter in the local universe and test cosmological models. However, present measurements of peculiar velocities are based on empirical distance indicators,…
The diverse and complex light curves of gamma-ray bursts (GRBs) remain an outstanding astrophysical mystery. Here we report the results of 2-1/2-dimensional particle-in-cell (PIC) simulations of the relativistic expansion of magnetized…
We make an attempt to dynamically study, in four space-time dimensions, the classical gravitational collapse of a macroscopic circular fundamental string, by a truncation of the Einstein equations that suppresses retarded features but keeps…
We consider the bending angle of the trajectory of a photon incident from and deflected to infinity around a Reissner-Nordstr\"om black hole. We treat the bending angle as a function of the squared reciprocal of the impact parameter and the…
We use the basic equations that predict the emission of gravitational waves according to the Einstein gravitation theory to calculate the luminosities and the amplitudes of the waves generated by binary stars, pulsations of neutron stars,…
This paper investigates the novel phenomenon of gravitational lensing experienced by gravitational waves traveling past a Schwarzschild black hole perturbed by a specific, first-order, polar gravitational wave. We utilize the Gauss-Bonnet…
A key observational prediction of Einstein's Equivalence Principle is that light undergoes redshift when it escapes from a gravitational field. Although astrophysics provides a wide variety of physical conditions in which this redshift…
When rotation is not taken into account, the measurement of the Gravitational Redshift can provide unique information about the compactness ($M/R$) of the star. Rotation alters the gravitational redshift rendering thereby a unique…
We review matter wave and clock comparison tests of the gravitational redshift. To elucidate their relationship to tests of the universality of free fall (UFF), we define scenarios wherein redshift violations are coupled to violations of…
That light propagating in a gravitational field gets frequency-shifted is one of the basic consequences of any metric theory of gravity rooted in the equivalence principle. At the same time, also a time dependent material's refractive index…
Gravitational lensing can be used to analyze the redshift distribution of faint galaxies. In particular the magnification bias modifies locally the galaxy number density of lensed sources observed in lensing clusters. This depletion area…
Recently, we proposed a novel charged wormhole spacetime based on Yoshiaki Sofue's exponential dark matter density profile, referred to as the Charged Galactic Wormhole. Our previous work explored the deflection of light and massive…
Attention is drawn to the fact that the well-known expression for the red-shift of spectral lines due to a gravitational field may be derived with no recourse to the theory of general relativity. This raises grave doubts over the inclusion…
The Wheeler-DeWitt Equation represents a tool to study Quantum Gravity and Quantum Cosmology. Its solution in a very general context is, of course, impossible. To this purpose we consider some distortions of General Relativity like…
We present analytical solutions of the geodesic equations of test particles and light in the five dimensional singly spinning black ring spacetime for special cases, since it does not appear possible to separate the Hamilton-Jacobi-equation…
In this letter we calculate the emission of gravity waves by the binary pulsar in the framework of five dimensional braneworlds. We consider only spacetimes with one compact extra-dimension. We show that the presence of additional degrees…
Due to their highly luminous nature, gamma-ray bursts (GRBs) are useful tools in studying the early Universe (up to z = 10). We consider whether the available subset of Swift high redshift GRBs are unusual when compared to analogous…
There are numerous reasons to study modifications of general relativity and the Standard Model of particle physics, ranging from modelling inflation to exploring galaxy rotation curves and the nature of dark matter. Here we study the most…
The chiral lattice structure of twisted bilayer graphene with D6 symmetry allows for intrinsic photogalvanic effects only at off-normal incidence, while additional extrinsic effects are known to be induced by a substrate or a gate…