The Motion of Spinning Particles in the Spacetime of a Black Hole with a Cosmic String Topological Defect

2014 ◽  
Vol 31 (9) ◽  
pp. 090402
Author(s):  
Chu-Yu Lai ◽  
Ju-Hua Chen ◽  
Yong-Jiu Wang
Keyword(s):  
Black Hole ◽  
Cosmic String ◽  
Topological Defect ◽  
Spinning Particles

TWO FAMILIES OF EXACT DISKS WITH A CENTRAL BLACK HOLE

1996 ◽  
Vol 05 (01) ◽  
pp. 53-63 ◽  
Author(s):  
JOSÉ P.S. LEMOS ◽  
PATRICIO S. LETELIER
Keyword(s):  
Black Hole ◽  
Topological Defect ◽  
Rotational Velocity ◽  
The Other ◽  
Central Black Hole ◽  
Counter Rotation ◽  
Infinite Extent ◽  
Self Similar ◽  
Physical Effects ◽  
Many Particles

The gravitational field of a configuration formed by a static disk and a Schwarzschild black hole is analysed for two families of disks. The matter of the disks is made of counter-rotating particles with as many particles rotating to one side as to the other, in such a way that the net angular momentum is zero and the disk is static. The first family consists of peculiar disks, in the sense that they are generated by two opposite dipoles. The particles of the disk have no pressure or centrifugal support. However, when there is a central black hole, centrifugal balance in the form of counter-rotation appears. The second family is a one parameter family of self-similar disks which includes at one end a Newtonian disk, and at the other a topological defect of spacetime. The presence of the black hole impresses more rotational velocity to the particles. These two families are of infinite extent. Some interesting physical effects are studied.

scholarly journals Charged particle dynamics in the surrounding of Schwarzschild anti-de Sitter black hole with topological defect immersed in an external magnetic field

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Sidra Shafiq ◽  
Saqib Hussain ◽  
Muhammad Ozair ◽  
Adnan Aslam ◽  
Takasar Hussain
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Event Horizon ◽  
Topological Defect ◽  
Magnetic Field Effect ◽  
Topological Defects ◽  
De Sitter ◽  
Relativistic Jets ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit

Abstract In this paper, geodesic motion of the charged particles in the vicinity of event horizon of Schwarzschild anti-de-Sitter black hole (BH) with topological defects has been investigated. Weakly magnetized environment is considered in the surrounding of BH which only effects the motion of the particles and doesn’t effect the geometry of the BH. Hence, particles are under the influence of gravity and electromagnetic forces. We have explored the effect of magnetic field on the trajectories of the particles and more importantly on the position of the innermost stable circular orbit. It is observed that the trajectories of the particles in the surrounding of BH are chaotic. Escape conditions of the particles under the influence of gravitomagnetic force are also discussed. Moreover, the escape velocity of particles and its different features have been investigated in the presence and absence of magnetic field. Effect of dark energy on the size of event horizon, mass of the BH and stability of the orbits of the particles have also been explored in detail. These studies can be used to estimate the power of relativistic jets originated from the vicinity of BH.

Gravitational Effects of a Black Hole with Cosmic String

2014 ◽  
Vol 54 (4) ◽  
pp. 1175-1183
Author(s):  
Chuyu Lai ◽  
Juhua Chen ◽  
Yongjiu Wang
Keyword(s):  
Black Hole ◽  
Cosmic String ◽  
Gravitational Effects

scholarly journals THE CIRCULAR LOOP EQUATION OF A COSMIC STRING WITH TIME-VARYING TENSION

2008 ◽  
Vol 23 (35) ◽  
pp. 3023-3030 ◽  
Author(s):  
HONGBO CHENG ◽  
YUNQI LIU
Keyword(s):  
Black Hole ◽  
Cosmic String ◽  
Cosmic Time ◽  
Minkowski Spacetime ◽  
Critical Value ◽  
Time Dependent ◽  
Time Varying ◽  
Circular Loop ◽  
Loop Equation

The equation of circular loops of cosmic string with time-dependent tension is studied in the Minkowski spacetime and Robertson–Walker universe. We found that, in the case where the tension depends on some power of the cosmic time, cosmic string loops with time-varying tension should not collapse to form a black hole if the power is lower than a critical value.

scholarly journals GRAVITATIONAL CAPTURE OF COSMIC STRINGS BY A BLACK HOLE

1998 ◽  
Vol 07 (06) ◽  
pp. 957-967 ◽  
Author(s):  
JEAN-PIERRE DE VILLIERS ◽  
VALERI FROLOV
Keyword(s):  
Black Hole ◽  
Impact Parameter ◽  
Cosmic String ◽  
Initial Velocity ◽  
Cosmic Strings ◽  
Gravitational Interaction ◽  
Equations Of Motion ◽  
Great Distance ◽  
Schwarzschild Black Hole ◽  
Gravitational Capture

The gravitational interaction of an infinitely long cosmic string with a Schwarzschild black hole is studied. We consider a straight string that is initially at a great distance and moving at some initial velocity v (0 < v < c) towards the black hole. The equations of motion of the string are solved numerically to obtain the dependence of the capture impact parameter on the initial velocity.

scholarly journals QUASINORMAL MODES OF RN BLACK HOLE SPACETIME WITH COSMIC STRING IN A DIRAC FIELD

2009 ◽  
Vol 24 (25) ◽  
pp. 2025-2037 ◽  
Author(s):  
R. SINI ◽  
V. C. KURIAKOSE
Keyword(s):  
Black Hole ◽  
Cosmic String ◽  
Quasinormal Modes ◽  
Potential Method ◽  
Dirac Field ◽  
Black Hole Spacetimes ◽  
Black Hole Spacetime ◽  
Field Decay ◽  
Positively Charged ◽  
Small Charge

We evaluate quasinormal mode frequencies for RN black hole spacetimes with cosmic string perturbed by a massless Dirac field, using Pöschl–Teller potential method. We find that only in the case of RN black hole having small charge, the effect due to cosmic string will dominate when perturbed by a negatively charged Dirac field, but if we are perturbing with positively charged Dirac field decay will be less in the case of black hole having cosmic string compared to the RN black hole without string.

scholarly journals Polarimetric signatures of the photon ring of a black hole that is pierced by a cosmic axion string

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Alexander Gußmann
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Formation Mechanism ◽  
Cosmic String ◽  
Cosmic Strings ◽  
Supermassive Black Holes ◽  
Rotating Black Hole ◽  
Aharonov Bohm ◽  
Polarized Photons

Abstract A black hole image contains a bright ring of photons that have closely circled the black hole on their way from the source to the detector. Here, we study the photon ring of a rotating black hole which is pierced by a global hyper-light axion-type cosmic string. We show that the coupling 𝜙F$$ \overset{\sim }{F} $$ F ~ between the axion 𝜙 and the photon can give rise to a unique polarimetric structure of the photon ring. The structure emerges due to an Aharonov-Bohm type effect that leads to a change of the polarization directions of linear polarized photons when they circle the black hole. For several parameter choices, we determine concrete polarization patterns in the ring. Measuring these patterns can provide us with a way of determining the value of the coefficient of the mixed anomaly between electromagnetism and the symmetry that gave rise to the cosmic string. Finally, we briefly review a possible formation mechanism of black holes that are pierced by cosmic strings and discuss under which conditions we can expect such objects to be present as supermassive black holes in the center of galaxies.

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.

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