Related papers: Electromagnetic fields around black holes and Meis…
An exact and analytical solution, in four-dimensional general relativity coupled with Maxwell electromagnetism, is built by means of a Lie point symmetry of the Ernst equations, the Harrison transformation. The new spacetime describes a…
Charged massive scalar fields are considered in the gravitational and electromagnetic field produced by a dyonic black hole with a cosmic string along its axis of symmetry. Exact solutions of both angular and radial parts of the covariant…
The most general electrically and magnetically charged rotating black hole solutions of 5 dimensional \KK\ theory are given in an explicit form. Various classical quantities associated with the black holes are derived. In particular, one…
Point charge, radially moving in the vicinity of a black hole is considered. Electromagnetic field in wave zone and in the small neighbourhood of the charge is calculated. Numerical results of the calculation of the spectrum of…
The Einstein-Maxwell theory has black hole solutions with electric and magnetic charges. In the standard model for particle physics, dyons with electric and magnetic charges would have been formed in the early universe. We derive the…
We construct exact solutions, which represent regular charged rotating Kaluza-Klein multi-black holes in the five-dimensional pure Einstein-Maxwell theory. Quantization conditions between the mass, the angular momentum, and charges appear…
Motivated by string theory corrections of dilatonic gravity and Born-Infeld nonlinear electromagnetic field, we consider the BTZ black holes with these two generalizations. It will be shown that the generalization to dilatonic gravity…
We study stationary slowly rotating black holes, up to quadratic order in the spin angular momentum, in dynamical Chern-Simons gravity and shift symmetric Einstein scalar Gauss-Bonnet gravity, as models of string-inspired gravities. These…
Born-Infeld black holes in the Scalar-Tensor Theories of Gravity, in the case of massless scalar field, have been recently obtained. The aim of the current paper is to study the effect from the inclusion of a potential for the scalar field…
We investigate the motion of charged particles evolving around a magnetized Kiselev black hole, in the weak magnetic field approximation. The effective potential allows us to study the bound motion and the stable circular orbits. We analyze…
A way to test electromagnetic field and spacetime properties around black holes is by considering the dynamics of test particles. In fact, in real astrophysical scenarios, it is hard to determine spacetime geometry which is dominating due…
We show that strongly coupled field theories with holographic gravity duals at finite charge density and low temperatures can undergo de Haas - van Alphen quantum oscillations as a function of an external magnetic field. Exhibiting this…
We study aspects of four dimensional black holes with two electric charges, corresponding to fundamental strings with generic momentum and winding on an internal circle. The perturbative \alpha' correction to such black holes and their…
The new, rapidly developing field of theoretical research --- studies of dark energy interacting with black holes (and, in particular, accreting onto black holes) --- is reviewed. The term `dark energy' is meant to cover a wide range of…
The electromagnetic (EM) perturbations of the black hole solutions in general relativity coupled to nonlinear electrodynamics (NED) are studied for both electrically and magnetically charged black holes, assuming that the EM perturbations…
We reconsider the problem of the formation of a large-scale magnetic field in the accretion disks around black holes. In contrast with previous work we take into account the nonuniform vertical structure of the disk. The high electrical…
One of the methods of study of black holes in astrophysics is based on broadening of the spectrum of radiation of ionized Iron atoms. The line K$\alpha$ associated with Iron emission at 6.4 keV is very narrow. If such an ion is revolving…
We investigate the dynamics of a neutral and a charged particle around a static and spherically symmetric black hole in the presence of quintessence matter and external magnetic field. We explore the conditions under which the particle…
The Schr\"odinger equation is solved for the wave function of an electron moving in a superposition of external constant and uniform electric and magnetic fields at an arbitrary angle between the field directions. The changing of the…
This thesis applies techniques from quantum field theory in curved spacetimes to study particle creation in external fields, focusing on the Schwinger effect (i.e., the production of particle-antiparticle pairs by intense electric fields).…