Related papers: Horizon Straddling ISCOs in Spherically Symmetric …
Using the exact solution that describes multi-centered rotating black holes, recently discovered by Teo and Wan, we investigate the innermost stable circular orbit (ISCO) for massive particles and the circular orbit for massless particles…
We study linear nonradial perturbations and stability of a marginal stable circular orbit (MSCO) such as the innermost stable circular orbit (ISCO) of a test particle in stationary axisymmetric spacetimes which possess a reflection symmetry…
The motion of classical spinning test particles in the equatorial plane of a Kerr black hole is considered for the case where the particle spin is perpendicular to the equatorial plane. We review some results of our recent research of the…
We conduct a comprehensive study on spherical orbits around two types of black holes: Kerr-Newman black holes, which are charged, and Ghosh black holes, which are nonsingular. In this work, we consider both null and timelike cases of…
Null and timelike equatorial orbits are investigated in a family of hairy black holes in the cubic Galileon theory. These include rotating generalizations of static black hole metrics supporting a time-dependent scalar field. Depending on…
We study collision of particles in the vicinity of a horizon of a weakly magnetized non-rotating black hole. In the presence of the magnetic field innermost stable circular orbits (ISCO) of charged particles can be located close to the…
Recently, a novel $4D$ Einstein-Gauss-Bonnet (EGB) gravity was formulated and a spherically symmetric black hole solution in this theory was derived by D. Glavan and C. Lin \cite{Glavan:2019inb}. In this paper, we study the geodesic motions…
In this paper, we have investigated the geodesics of neutral particles near a five-dimensional charged black hole using a comparative approach. The effective potential method is used to determine the location of the horizons and to study…
We consider the escape probability of a photon emitted from the innermost stable circular orbit (ISCO) of a rapidly rotating black hole. As an isotropically emitting light source on a circular orbit reduces its orbital radius, the escape…
Static black holes contain regions of spacetime which not even light can escape from. In the centre of mass frame, these blocks are separated from each other by event horizons. Unlike pointlike particles, fields can spread and interact…
In this paper, some dynamical properties of neutral and charged particles around a weakly magnetized five-dimensional static black string have been studied. The perturbation method was also used to calculate the Innermost Stable Circular…
We examine the possibility of arbitrarily high energy in the Center-of-mass(CM) frame of colliding neutral particles in the vicinity of the horizon of a charged dilation black hole(BH). We show that it is possible to achieve the infinite…
This article investigates the presence of a static spherically symmetric solution in the metric f(R) gravity. Consequently, we have examined the presence of horizons for the extreme and hyperextreme Schwarzschild-de Sitter solution.…
Recently, an analytical study of radial and circular orbits for null and time-like geodesics that propagate in the spacetime produced by a Schwarzschild black hole associated with cloud of strings, in a universe filled by quintessence, has…
In the spacetime of horizonless compact objects described by Einsteinian cubic gravity (ECG), we demonstrate the existence of static stable timelike circular orbits on which massive particles remain at rest relative to distant observers.…
In this work we derived a rotating and non-linear magnetic-charged black hole surrounded by quintessence using the Newman-Janis algorithm. Considering the state parameter $\omega_q=-3/2$, we studied the event horizons, the ergosphere, and…
Light propagating from near a black hole horizon to the outside world is highly redshifted. In the limit that the emitter passes through the horizon, the redshift becomes infinite. In this sense the near horizon region is unobservable, as…
In this article we study the innermost stable circular orbit (ISCO) of electrically charged particles in the electrically charged Reissner-Nordstr\"om spacetime, the Kerr-Newman spacetime and the Kerr-Sen spacetime. We find that the radius…
The fact that one must evaluate the near-extremal and near-horizon limits of Kerr space-time in a specific order, is shown to a lead to discontinuity in the extremal limit, such that this limiting space-time differs nontrivially from the…
The collision of test charged particles in the vicinity of an event horizon of a weakly magnetized non-rotating black hole with gravitomagnetic charge has been studied. The presence of the external magnetic field decreases the innermost…