scholarly journals Characteristic Orbits Of Charged Particles Around Charged Black Holes

2021 ◽  
Vol 03 (04) ◽  
pp. 78-83
Author(s):  
Xudoyberdiyeva Malika Karomat Qizi ◽  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Boundary Conditions ◽  
Accretion Disk ◽  
Charged Particles ◽  
Circular Orbits ◽  
Charged Black Holes ◽  
Lower Limits

We have considered Reissner-Nordstr¨om (RN) charged nonrotating black hole (BH).We have studied motion of charged particles around charged RN BH. It was found out that there are two boundary conditions for specific angular momentum of stable circular orbits corresponding to: innermost stable circular orbits (ISCO) and outermost stable circular orbits (OSCO) and accretion disk is originated between these two orbits. It was obtained the upper and lower limits for the value of particle’s charge which may exist in the accretion disk matter around the extreme charged Reissner Nordstr¨om black hole.

scholarly journals CHARGED ROTATING BLACK HOLES IN DILATON GRAVITY

2007 ◽  
Vol 22 (26) ◽  
pp. 4849-4858 ◽  
Author(s):  
A. SHEYKHI ◽  
N. RIAZI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Dilaton Field ◽  
Dilaton Gravity ◽  
Charged Black Holes ◽  
Static Solutions ◽  
Rotating Black Holes ◽  
Small Rotation ◽  
Type Potential

We consider charged black holes with curved horizons, in five-dimensional dilaton gravity in the presence of Liouville-type potential for the dilaton field. We show how, by solving a pair of coupled differential equations, infinitesimally small angular momentum can be added to these static solutions to obtain charged rotating dilaton black hole solutions. In the absence of dilaton field, the nonrotating version of the solution reduces to the five-dimensional Reissner–Nordström black hole, and the rotating version reproduces the five-dimensional Kerr–Newman modification thereof for small rotation parameter. We also compute the angular momentum and the angular velocity of these rotating black holes which appear at the first order.

MULTI-BLACK HOLES SOLUTION WITH COSMIC STRINGS

2004 ◽  
Vol 19 (10) ◽  
pp. 1549-1557 ◽  
Author(s):  
F. ÖZDEMIR ◽  
N. ÖZDEMIR ◽  
B. T. KAYNAK
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Cosmic String ◽  
Circular Orbit ◽  
Cosmic Strings ◽  
De Sitter ◽  
Circular Orbits ◽  
Small Oscillations ◽  
String Models

Some black hole-cosmic string models such as Reissner–Nordström, RN–de Sitter, Kerr–Newman and multi-black holes with cosmic string are given. Energy and angular momentum of a timelike particle in circular orbits in multi-black hole space–time are calculated. The geodesic equations for the timelike particles for the far region of the multi-black hole sources are calculated and small oscillations around the circular orbit obtained. It is seen that the particle's orbit precesses like the Lens–Thirring effect.

scholarly journals MOTION OF CHARGED PARTICLES ON THE REISSNER–NORDSTRÖM (ANTI)-DE SITTER BLACK HOLE SPACETIME

2011 ◽  
Vol 26 (39) ◽  
pp. 2923-2950 ◽  
Author(s):  
MARCO OLIVARES ◽  
JOEL SAAVEDRA ◽  
CARLOS LEIVA ◽  
JOSÉ R. VILLANUEVA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Charged Particles ◽  
De Sitter ◽  
Point Particles ◽  
Charged Black Holes ◽  
Black Hole Spacetime ◽  
Jacobi Functions ◽  
Electrically Charged ◽  
Charged Point

We study the motion of relativistic, electrically charged point particles in the background of charged black holes with nontrivial asymptotic behavior. We compute the exact trajectories of massive particles and express them in terms of elliptic Jacobi functions. As a result, we obtain a detailed description of particles orbits in the gravitational field of Reissner–Nordström (anti)-de Sitter black hole, depending of their charge, mass and energy.

scholarly journals Growing Supermassive Black Holes Inside Cosmological Simulations

2009 ◽  
Vol 5 (S267) ◽  
pp. 333-333
Author(s):  
Robyn Levine ◽  
Nickolay Y. Gnedin ◽  
Andrew J. S. Hamilton
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Accretion Disk ◽  
Adaptive Mesh Refinement ◽  
Adaptive Mesh ◽  
Outer Edge ◽  
Central Black Hole ◽  
Supermassive Black Hole ◽  
Circumnuclear Disk

Using a hydrodynamic adaptive mesh refinement code, we simulate the growth and evolution of a typical disk galaxy hosting a supermassive black hole (SMBH) within a cosmological volume. The simulation covers a dynamical range of 10 million, which allows us to study the transport of matter and angular momentum from super-galactic scales down to the outer edge of the accretion disk around the SMBH. A dynamically interesting circumnuclear disk develops in the central few hundred parsecs of the simulated galaxy, through which gas is stochastically transported to the central black hole.

scholarly journals Properties of Black Holes Relevant to their Observation

1974 ◽  
Vol 64 ◽  
pp. 132-144 ◽  
Author(s):  
James M. Bardeen
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Hot Spots ◽  
Binary Systems ◽  
X Rays ◽  
Circular Orbits ◽  
Spacetime Geometry ◽  
Inertial Frames ◽  
Physical Effects

Black holes are very small objects by astronomical standards, so in many circumstances they interact with their surroundings like a Newtonian mass point. However, if black holes are present in X-ray binary systems, the X-rays emitted in the inner part of the accretion disk probe the highly curved spacetime geometry near the horizon, particularly if the black hole is rapidly rotating. Some of the properties of circular orbits near the black hole are quite sensitive to the amount of angular momentum. The relativistic corrections remove a Newtonian degeneracy between several of the characteristic frequencies associated with perturbations of the circular orbits.Hot spots in the inner part of the disk can produce dramatic fluctuations in intensity, since the frequency shifts of photons emitted by a given point on the disk are strongly time-dependent. The bending of the photon trajectories by the strong gravitational field can drastically affect the energy balance of the disk; much of the radiation emitted by the inner part of the disk is reabsorbed. The dragging of inertial frames by the angular momentum of the black hole can have striking consequences for the structure of the disk at quite large radii if the angular momentum of the accreting matter is not in the same direction as the angular momentum of the black hole.Dynamic perturbations of black holes are now being intensively studied to see if there are any surprising physical effects associated with the rotation of the black hole. Unfortunately, though quite interesting methods of extracting energy from the black hole exist in principle most of them are unlikely to be realized to an important extent in the real astrophysical world.

R-N black holes can be transformed into K-N black holes

2021 ◽  
Author(s):  
Wen-Xiang Chen
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Boundary Conditions ◽  
Black Hole Entropy ◽  
Charged Black Hole ◽  
Naked Singularities ◽  
Hole Charge

If there is no strong cosmic supervision conjecture, there may be naked singularities. The decrease in black hole entropy indicates that there is periodicity inside the black hole.This article points out that when the entropy of a black hole decreases, its enthalpy will increase, and the black hole charge will be converted into angular momentum through a certain channel. This article hereby asserts that a non-rotating charged black hole will transform into a rotating charged black hole under the effect of superradiation under preset boundary conditions.

scholarly journals New non-extremal and BPS hairy black holes in gauged $$ \mathcal{N} $$ = 2 and $$ \mathcal{N} $$ = 8 supergravity

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Andres Anabalon ◽  
Dumitru Astefanesei ◽  
Antonio Gallerati ◽  
Mario Trigiante
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Boundary Conditions ◽  
Charged Black Hole ◽  
Dual Theory ◽  
Real Numbers ◽  
Hairy Black Holes ◽  
Interpolation Parameter ◽  
Black Hole Solutions ◽  
Extremal Black Holes

Abstract In this article we study a family of four-dimensional, $$ \mathcal{N} $$ N = 2 supergravity theories that interpolates between all the single dilaton truncations of the SO(8) gauged $$ \mathcal{N} $$ N = 8 supergravity. In this infinitely many theories characterized by two real numbers — the interpolation parameter and the dyonic “angle” of the gauging — we construct non-extremal electrically or magnetically charged black hole solutions and their supersymmetric limits. All the supersymmetric black holes have non-singular horizons with spherical, hyperbolic or planar topology. Some of these supersymmetric and non-extremal black holes are new examples in the $$ \mathcal{N} $$ N = 8 theory that do not belong to the STU model. We compute the asymptotic charges, thermodynamics and boundary conditions of these black holes and show that all of them, except one, introduce a triple trace deformation in the dual theory.

scholarly journals Gaseous Disks in the Nuclei of Elliptical Galaxies

1997 ◽  
Vol 163 ◽  
pp. 620-625 ◽  
Author(s):  
H. Ford ◽  
Z. Tsvetanov ◽  
L. Ferrarese ◽  
G. Kriss ◽  
W. Jaffe ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Accretion Disks ◽  
Large Scale ◽  
Elliptical Galaxies ◽  
Central Mass ◽  
Massive Black Holes ◽  
Radio Jets

AbstractHST images have led to the discovery that small (r ~ 1″ r ~ 100 – 200 pc), well-defined, gaseous disks are common in the nuclei of elliptical galaxies. Measurements of rotational velocities in the disks provide a means to measure the central mass and search for massive black holes in the parent galaxies. The minor axes of these disks are closely aligned with the directions of the large–scale radio jets, suggesting that it is angular momentum of the disk rather than that of the black hole that determines the direction of the radio jets. Because the disks are directly observable, we can study the disks themselves, and investigate important questions which cannot be directly addressed with observations of the smaller and unresolved central accretion disks. In this paper we summarize what has been learned to date in this rapidly unfolding new field.

OF CHARGED STARS AND CHARGED BLACK HOLES

2004 ◽  
Vol 13 (07) ◽  
pp. 1375-1379 ◽  
Author(s):  
MANUEL MALHEIRO ◽  
RODRIGO PICANÇO ◽  
SUBHARTHI RAY ◽  
JOSÉ P. S. LEMOS ◽  
VILSON T. ZANCHIN
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Charged Particle ◽  
Equation Of State ◽  
Mass Density ◽  
Compact Star ◽  
Maximum Amount ◽  
Stellar Structure ◽  
Charged Black Holes ◽  
Polytropic Equation

Effect of maximum amount of charge a compact star can hold, is studied here. We analyze the different features in the renewed stellar structure and discuss the reasons why such huge charge is possible inside a compact star. We studied a particular case of a polytropic equation of state (EOS) assuming the charge density is proportional to the mass density. Although the global balance of force allows a huge charge, the electric repulsion faced by each charged particle forces it to leave the star, resulting in the secondary collapse of the system to form a charged black hole.

Boundary conditions for Maxwell fields in Kerr-AdS spacetimes

2016 ◽  
Vol 25 (09) ◽  
pp. 1641011 ◽  
Author(s):  
Mengjie Wang
Keyword(s):  
Black Holes ◽  
Angular Momentum ◽  
Boundary Conditions ◽  
Energy Flux ◽  
Momentum Flux ◽  
De Sitter ◽  
Perturbative Methods ◽  
Flux Boundary Conditions ◽  
Maxwell Fields ◽  
New Type

Perturbative methods are useful to study the interaction between black holes and test fields. The equation for a perturbation itself, however, is not complete to study such a composed system if we do not assign physically relevant boundary conditions. Recently we have proposed a new type of boundary conditions for Maxwell fields in Kerr-anti-de Sitter (Kerr-AdS) spacetimes, from the viewpoint that the AdS boundary may be regarded as a perfectly reflecting mirror, in the sense that energy flux vanishes asymptotically. In this paper, we prove explicitly that a vanishing energy flux leads to a vanishing angular momentum flux. Thus, these boundary conditions may be dubbed as vanishing flux boundary conditions.

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