Related papers: Probing the Brans-Dicke Gravitational Field by Cer…
Charged particles in the geodesic trajectory of an external gravitational field do not emit electromagnetic radiation. This is expected from the application of the equivalence principle. We show here that charged particles propagating in an…
Contrary to common belief, the standard tenet of Brans-Dicke theory reducing to general relativity when omega tends to infinity is false if the trace of the matter energy-momentum tensor vanishes. The issue is clarified in a new approach…
The propagation of boson particles in a gravitational field described by the Brans-Dicke theory of gravity is analyzed. We derive the wave function of the scalar particles, and the effective potential experienced by the quantum particles…
The Brans-Dicke Theory of Gravity is one of the most promising alternatives to the Einstein's Theory of General Relativity. We have examined an action term with wrong signs for both the kinetic and mass terms for the scalar field and have…
This note revisits and corrects a previous analysis on gravitational radiation in compact binary systems within the framework of Brans-Dicke-f(R) theories-models featuring both massless and effectively massive scalar fields. We correct the…
The emission of electromagnetic radiation by charges moving uniformly in a Lorentz-violating vacuum is studied. The analysis is performed within the classical Maxwell-Chern-Simons limit of the Standard-Model Extension (SME) and confirms the…
A covariant criterion for the Cherenkov radiation emission in the field of a non-linear gravitational wave is considered in the framework of exact integrable models of particle dynamics and electromagnetic wave propagation. It is shown that…
Brans-Dicke gravity admits spherical solutions describing naked singularities rather than black holes. Depending on some parameters entering such a solution, stable circular orbits exist for all radius. One argues that, despite the fact…
This article presents a theoretical limit on the Brans-Dicke (BD) parameter using a neutron star (NS) revolving around a galactic central engine.The assumption that the orbital radius is large enough allows to ignore strong curvature due to…
It is well-known that a charged particle moving with constant velocity in vacuum does not radiate. In a medium the situation can be different. If the so called Cherenkov condition is satisfied, i.e. the particle velocity exceeds the phase…
We explore the possibility that a charged particle moving in the gravitational field generated by a scalar star could radiate energy via a recently proposed gravitational \v{C}erenkov mechanism. We numerically prove that this is not…
We investigate the hypothetical process of gravitational Cherenkov radiation, which may occur in modified gravity theories. We obtain a useful constraint on a modified dispersion relation for propagating modes of gravitational waves, which…
Some characteristic features in the radiation from a relativistic electron uniformly rotating along an equatorial orbit around a dielectric ball have been studied. It was shown that at some harmonics, in case of weak absorption of radiation…
Effects of a 4d dilaton field on a falling test mass are examined from the Einstein frame perspective of scalar-tensor theory. Results are obtained for the centripetal acceleration of particles in circular orbits, and the radial…
Radiation generated by a charge moving through a vacuum channel in a dielectric cone is analyzed. It is assumed that the charge moves through the cone from the apex side to the base side (the case of "inverted" cone). The cone size is…
We linearize the field equations for higher order theories of gravity that contain scalar invariants other than the Ricci scalar. We find that besides a massless spin-2 field (the standard graviton), the theory contains also spin-0 and…
Gravitational field of a nonstatic global string has been studied in the context of Brans-Dicke theory of gravity. Both the metric components and the BD scalar field are assumed to be nonseparable functions of time and space.The spacetime…
The Cerenkov radiation of a neutral particle with magnetic moment is considered, as well as the spin-dependent contribution to the Cerenkov radiation of a charged spinning particle. The corresponding radiation intensity is obtained for an…
We investigate how the gravitational field generated by line sources can be characterized in Brans-Dicke theory of gravity. Adapting an approach previously developed by Israel who solved the same problem in general relativity we show that…
The radiation from a relativistic charged particle uniformly moving through the centre of a dielectric ball is investigated. Analytical expressions for spectral and spectral-angular distributions of the radiated energy are derived and…