The aim of the paper is the consideration of particle collisions in the vicinity of the horizon of rotating black holes. Existence of geodesics for massive and massless particles arising from the region inside of the gravitational radius in ergosphere leads to the different possibilities to get very high energy in the centre mass frame of two particles. The classification of all such geodesics on the basis of the proved theorem for extremal spherical orbits is given. Case of the unlimited growth of energy for the situation when one of the particles (the critical one) is moving along the "white hole" geodesic with the close to the upper limit angular momentum while the other particle is on the usual geodesic and the case of the unlimited negative angular momentum of the first particle are considered.
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 electromagnetic radiation of the point charge are presented. Covariant approach for the calculation of electromagnetic self-force is used for the case of the slowly moving charge. Numerical results for the self-force in the case of slow motion of the particle are obtained and compared to the results in literature.
We consider a cluster of Primordial Black Holes which is decoupled from the cosmological expansion (Hubble flow) and this region is heated as compared to the surrounding matter. The increased temperature inside the region can be explained by several mechanisms of Primordial Black Holes formation. We study the temperature dynamics of the heated region of Primordial Black Holes cluster.
Recently, two kinds of deformed schwarzschild spacetime have been proposed, which are the black-bounces metric (\cite{2019JCAP...02..042S,2021PhRvD.103h4052L}) and quantum deformed black hole (BH) (\cite{2021arXiv210202471B}). In present work, we investigate the rotating spacetime of these deformed Schwarzschild metric. They are exact solutions to the Einstein$'$s field equation. We analyzed the properties of these rotating spacetimes, such as event horizon (EH), stationary limit surface (SIS), structure of singularity ring, energy condition (EC), etc., and found that these rotating spacetime …
One of the solutions of Einstein field equation with cylindrical symmetry is known as black string solution. In this work, the rotating black string solution in dRGT massive gravity is obtained and then called rotating-dRGT black string solution. This solution is a kind of generalized version of rotating AdS/dS black sting solution containing an additional two more terms characterizing the structure of graviton mass. The horizon structures of the black string are explored. The thermodynamical properties of the black string are investigated. We found that it is possible to obtain the Hawking-Pa…
Entropy bound for a rotating system from Anti de Sitter black holes
得到了自旋系统围绕（3+1）维和（2+1）维旋转反德西特黑洞运动的一般测地线方程。基于这些方程，我们分别导出了Kerr-Anti de Sitter黑洞和BTZ黑洞转动系统的熵界.我们的结果与由Kerr黑洞导出的Hod的结果一致，表明转动系统的熵界既不依赖于黑洞参数，也不依赖于时空维数.这是一个普遍的熵界。
Rotating and non-linear magnetic-charged black hole with an anisotropic matter field
School of Physics Science and Technology, Xinjiang University（新疆大学物理科学与技术学院）；Faculty of Science, Kunming University of Science and Technology（昆明理工大学理学院）
We find an analytic asymptotically anti-de Sitter solution for charged rotating black strings in Einsteinian quartic gravity. By studying the near-horizon behavior of the solutions, we independently extract their thermodynamic properties, analytically. As a consistency check, we show that the first law of thermodynamics for rotating black strings holds exactly in both charged and uncharged cases.
The Teukolsky wave equations governing fields of spin 0, $\tfrac{1}{2}$, 1, $\tfrac{3}{2}$, and 2 are generalized to the case of conformally separable solutions for accreting, rotating black holes.
With a semiclassical polymerization in the loop quantum gravity (LQG), the interior of Schwarzschild black holes provides a captivating single-horizon regular black hole spacetime. The shortage of rotating black hole models in loop quantum gravity (LQG) substantially restrains the progress of testing LQG from observations. Motivated by this, starting with a spherical LQG black hole as a seed metric, we construct a rotating spacetime using the revised Newman-Janis algorithm, namely, the LQG-motivated rotating black holes (LMRBH), which encompasses Kerr ($l=0$) black holes as an exceptional case…
We consider Einstein-Maxwell-Dilaton theory in $(2+1)$-dimensions where the coupling between the scalar field and the Maxwell invariant is the dilatonic coupling $f(ϕ) = \exp (-2αϕ)$ and obtain novel exact rotating black hole solutions. The dilatonic parameter $α$ impacts the metric function, affecting the rotating properties of the black hole, its mass and also its thermodynamics. Calculating the entropy we find that it is always positive and the dilatonic black holes may have higher entropy than the BTZ black hole. Depending on the parameters, the dilatonic BTZ-like black hole may be thermod…
Light deviation around a rotating black hole is calculated using the Kerr metric for both small and large deviation angles. For small angles the Lindstedt-Poincaré method is employed to get well-behaved solutions, as well as Padé approximants. For large deviation angles numerical integration has been used.
We demonstrate an optical realization for the rotating BTZ black hole using the recent popular photon fluid model in an optical vortex but with a new proposed expression for the optical phase. We also give the numerical realization for the optical vortex to ensure that it can be generated experimentally. Different from the earlier suggestions for the analogue rotating black holes, our proposal includes an inner horizon in the analogue black hole structure. Such structure can keep for a long distance for the convenience of observing analogue Hawking or Penrose radiations.
We find a charged spherically symmetric black hole solution with the existence of a cloud of strings and quintessential matter. Then we apply the Demianski-Newman-Janis algorithm to generate the rotating and twisting counterpart. The thermodynamic properties of this black hole solution are further investigated.
