相关论文: Redshift of light emitted by particles orbiting a …
We investigate the red/blue shifts of photons emitted by particles moving along stable circular orbits around a Hayward regular black hole immersed in perfect fluid dark matter (PFDM). The PFDM contribution modifies the horizon structure…
In this work we derive novel analytical expressions for the mass and distance of a Schwarzschild black hole (BH), as well as for the orbital radius of test particles orbiting it, it terms of astrophysical observables measured throughout the…
In this work, we study the motion of a magnetized particle orbiting a static and spherically symmetric black hole immersed in an external asymptotically uniform magnetic field in Einstein-dilaton-Gauss-Bonnet gravity. Similar to the…
The geodesic equations are considered in static mass imbedded in a uniform electromagnetic field. Due to electromagnetic field horizon shrinks and geodesics are modified. By analyzing the behavior of the effective potentials for the…
The classical phenomenon of the redshift of light in a static gravitational potential, usually called the gravitational redshift, is described in the literature essentially in two ways: on the one hand the phenomenon is explained through…
We study the effects of large scale magnetic fields on the dynamics of charged particles near a rotating black hole. We consider a scenario in which the initially neutral particles on geodesic orbits in the equatorial plane become ionized,…
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 consider a free-falling observer who crosses the event horizon in the Schwarzschild background. In the course of this fall, he/she can receive signals from an object (like a star surface) that emits radiation. We study how the frequency…
Non-static gravitational fields generally introduce frequency shifts when bending light. In this paper, I discuss the frequency shifts induced in the bending of light by moving masses. As examples, I treat the recently discovered…
This paper explores the dynamics of both neutral as well as charged particles orbiting near a rotating black hole in scalar-tensor-vector gravity. We study the conditions for the particle to escape at the innermost stable circular orbit. We…
To model magnetic fields of compact objects we solve the Maxwell equations in the background of the exterior static Schwarzschild and slowly rotating Kerr space-times. We impose the boundary condition that the electromagnetic fields are to…
The combined effect of a strong gravitational field and electromagnetic field in the vicinity of a generic regular black hole related to non-linear electrodynamics with Maxwellian weak-field limit on the radiation flux of a hot spot…
In this paper we have investigated the gravitational lensing phenomenon in the strong field regime for a regular, charged, static, non-linear black hole having a electrodynamics source. We have obtained the angle of deflection and compared…
In this note, we have analyzed the circular motion of test particles around the Schwarzschild-MOG black hole. First, we have studied the shadow cast by the spherical symmetric black hole within MOG gravity. It has been shown that due to the…
The work on black holes immersed in external stationary magnetic fields is reviewed in both test-field approximation and within exact solutions. In particular we pay attention to the effect of the expulsion of the flux of external fields…
The motion of superluminal particles in the gravitational field of a non-rotating black hole is analyzed. The relativistic Hamilton-Jacobi equation is solved for particles with imaginary rest mass. It is shown that there are no stable…
A new method is applied for deriving the redshift and shadow of a Schwarzschild black hole moving freely in the de Sitter expanding universe as recorded by a co-moving remote observer. This method is manly algebraic focusing on the…
A "temporal analogue" of the standard Poynting-Robertson effect is analyzed as induced by a dust of particles (instead of a gas of photons) surrounding a Schwarzschild black hole. Test particles inside this cloud undergo acceleration…
It is well known that supermassive black holes in the centers of galaxies are capable of accelerating charged particles to very high energies. In many cases, the particle acceleration by black holes occurs electromagnetically through an…
Magnetic fields surrounding spinning black holes can confine radiation and trigger superradiant instabilities. To investigate this effect, we perform the first fully-consistent linear analysis of the Ernst spacetime, an exact solution of…