Related papers: The Speed of Gravity
Gravitational wave observations have been used to test Lorentz symmetry by looking for dispersive effects that are caused by higher order corrections to the dispersion relation. In this Letter I argue on general grounds that, when such…
The present work aims to search for an implementation of new symmetries in the space-time in order to enable us to find a connection between electrodynamics and gravitation, from where quantum principles naturally emerge. To do that, first…
We investigate spacetimes in which the speed of light along flat 4D sections varies over the extra dimensions due to different warp factors for the space and the time coordinates (``asymmetrically warped'' spacetimes). The main property of…
We consider an Einstein-Maxwell action modified by the addition of three terms coupling the electromagnetic strength to the curvature tensor. The corresponding generalized Maxwell equations imply a variation of the speed of light in a…
The light curve of many supernovae (SNe) and gamma-ray bursts (GRBs) can be explained by a sustained injection of extra energy from its possible central engine, a rapidly rotating strongly magnetic neutron star (i.e. magnetar). The magnetic…
In this work, we study the magnetic effects of gravity in the framework of special relativity. Imposing covariance of the gravitational force with respect to the Lorentz transformations, we show from a thought experiment that a…
We study different manifestations of the speed of light in theories of gravity where metric and connection are regarded as independent fields. We find that for a generic gravity theory in a frame with locally vanishing affine connection,…
A number of theories of gravity have been proposed as proxies for dark matter in the regime of galaxies and cosmology. The recent observations of gravitational waves (GW170817) from the merger of two neutron stars, followed by an…
In some modified theories of gravity, gravitational waves can contain up to six different polarizations, which can travel at speeds different from that of light. Searches for these different polarizations in gravitational wave data are…
In this work we shall study Einstein Gauss-Bonnet theories and we investigate when these can have their gravitational wave speed equal to the speed of light, which is unity in natural units, thus becoming compatible with the striking event…
The purpose of this paper is to present mathematical evidence that electromagnetic near-field waves and wave groups, generated by an oscillating electric dipole, propagate much faster than the speed of light as they are generated near the…
It has been found in several papers that, because of quantum corrections, light front can propagate with superluminal velocity in gravitational fields and even in flat space-time across two conducting plates. We show that, if this is the…
We predict a new mechanism for the spin light of neutrino ($SL\nu$) that can be emitted by a neutrino moving in gravitational fields. This effect is studied on the basis of the quasiclassical equation for the neutrino spin evolution in a…
Strong lensing by intervening galaxies can produce multiple images of gravitational waves from sources at cosmological distances. These images acquire additional phase-shifts as the over-focused wavefront passes through itself along the…
The properties of light in the presence of electromagnetic and gravitational fields are compared. Once one takes account of the fact that clock rates vary with distance from a massive object, it is argued that in an absolute sense light…
The propagation speed of gravitational waves, $c_T$, has been tightly constrained by the binary neutron star merger GW170817 and its electromagnetic counterpart, under the assumption of a frequency-independent $c_T$. Drawing upon arguments…
We address a dynamical, spherically symmetric background in beyond Horndeski theory and formulate a set of linear stability conditions for high energy perturbation modes above an arbitrary solution. In this general setting we derive speeds…
We investigate the scalar induced gravitational waves which propagate with a speed different from the speed of light. First, we analytically calculate the expression of the power spectrum of the scalar induced gravitational waves which is…
We investigate in detail two physical properties of the metric f(R) theory developed by Sobouti (2007). We first look for the possibility of producing gravitational waves that travel at the speed of light. We then check the possibility of…
The gravitational energy shift for photons is extended to all mass-equivalent energies $E = mc^2$, obeying the quantum condition $E = h\nu$.On an example of a relativistic binary system, it was shown that the gravitational energy shift…