scholarly journals Dirac Monopoles in the Ernst–Schwarzschild Spacetime

2003 ◽  
Vol 18 (12) ◽  
pp. 2153-2157 ◽  
Author(s):  
A. A. Bytsenko ◽  
Yu. P. Goncharov
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
External Magnetic Field ◽  
Explicit Form ◽  
Hawking Radiation ◽  
Maxwell Equations ◽  
Schwarzschild Spacetime ◽  
Dirac Monopole ◽  
Schwarzschild Metric ◽  
The Given

It is discussed that the Ernst–Schwarzschild metric describing a nonrotating black hole in the external magnetic field admits the solutions of the Dirac monopole types for the corresponding Maxwell equations. The given solutions are obtained in explicit form and a possible influence of the conforming Dirac monopoles on Hawking radiation is also outlined.

scholarly journals Charged particle and epicyclic motions around 4D Einstein–Gauss–Bonnet black hole immersed in an external magnetic field

2020 ◽  
Vol 30 ◽  
pp. 100648 ◽  
Author(s):  
Sanjar Shaymatov ◽  
Jaroslav Vrba ◽  
Daniele Malafarina ◽  
Bobomurat Ahmedov ◽  
Zdeněk Stuchlík
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Charged Particle ◽  
External Magnetic Field

Effects of the external magnetic field on the Lense–Thirring precession

2021 ◽  
Author(s):  
Muhammad Rizwan ◽  
Tooba Feroze
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
External Magnetic Field ◽  
Equatorial Plane ◽  
Polar Axis ◽  
Precession Frequency ◽  
Black Hole Spacetime ◽  
Newman Black Hole

In this paper, we study the effects of the external magnetic field on the Lense–Thirring (LT) precession of a test gyroscope attached to an observer in magnetized black hole spacetime. For this, we consider a Kerr–Newman black hole embedded in the external magnetic field. The LT precession of a test gyroscope diverges near the ergosurface and remains finite everywhere outside the ergosurface. It is seen that by increasing the external magnetic field, the LT precession frequency in the region of large [Formula: see text] decreases as [Formula: see text] increases, while the precession frequency in the region of small [Formula: see text] increases as [Formula: see text] increases, whereas it increases with increasing the charge of the black hole. The LT precession of a test gyroscope attached to observers moving along the directions close to the polar axis is greater than that of the observer moving in the equatorial plane.

ON ERNST BLACK HOLES WITH A DILATON POTENTIAL

2005 ◽  
Vol 20 (14) ◽  
pp. 1077-1085 ◽  
Author(s):  
MARICEL AGOP ◽  
EUGEN RADU ◽  
REINOUD SLAGTER
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Black Hole ◽  
External Magnetic Field ◽  
Thermodynamic Properties ◽  
Action Principle ◽  
Schwarzschild Black Hole ◽  
Liouville Type ◽  
Background Magnetic Field ◽  
Type Potential

The dilatonic Ernst solution describing a Schwarzschild black hole immersed in a background magnetic field is generalized by including a Liouville-type potential in the action principle. We prove that the thermodynamic properties of this new black hole dilaton solution are unaffected by an external magnetic field passing through it.

MOTION OF CHARGED PARTICLES AROUND A FIVE-DIMENSIONAL ROTATING MAGNETIZED BLACK HOLE

2007 ◽  
Vol 16 (08) ◽  
pp. 1369-1379
Author(s):  
R. KAYA
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
External Magnetic Field ◽  
Effective Potential ◽  
Equatorial Plane ◽  
Charged Particles ◽  
Circular Motion ◽  
Test Particles ◽  
Jacobi Formalism ◽  
The Stability

We study the effect of an external magnetic field on the stability of circular motion of charged particles in the equatorial plane of a five-dimensional rotating black hole. Using the Hamilton–Jacobi formalism, we derive the effective potential for the radial motion of test particles around a five-dimensional magnetized Myers–Perry black hole. We show that there exist stable circular orbits in equatorial planes in the background of this metric.

scholarly journals DIRAC MONOPOLES AND HAWKING RADIATION IN KOTTLER SPACETIME

2002 ◽  
Vol 17 (32) ◽  
pp. 4947-4957
Author(s):  
A. A. BYTSENKO ◽  
YU. P. GONCHAROV
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Energy Density ◽  
Hawking Radiation ◽  
Natural Extension ◽  
Schwarzschild Black Hole ◽  
Complex Scalar ◽  
Radiation Process ◽  
Complex Scalar Field ◽  
The Given

The natural extension of Schwarzschild metric to the case of nonzero cosmological constant Λ known as the Kottler metric is considered and it is discussed under what circumstances the given metric could describe the Schwarzschild black hole immersed in a medium with nonzero energy density. Under the latter situation such an object might carry topologically inequivalent configurations of various fields. The given possibility is analyzed for complex scalar field and it is shown that the mentioned configurations might be tied with natural presence of Dirac monopoles on black hole under consideration. In turn, this could markedly modify the Hawking radiation process.

scholarly journals A NOTE ON SCHWARZSCHILD BLACK HOLE THERMODYNAMICS IN A MAGNETIC UNIVERSE

2002 ◽  
Vol 17 (34) ◽  
pp. 2277-2281 ◽  
Author(s):  
EUGEN RADU
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
External Magnetic Field ◽  
Thermodynamic Properties ◽  
Background Subtraction ◽  
Black Hole Thermodynamics ◽  
Schwarzschild Black Hole

We prove that the thermodynamic properties of a Schwarzschild black hole are unaffected by an external magnetic field passing through it. Apart from the background subtraction prescription, this result is also obtained by using a counterterm method.

Regulation Behavior of Microwave Reflectivity in Magnetorheological Fluids

2011 ◽  
Vol 413 ◽  
pp. 213-216
Author(s):  
Ji Jun Fan ◽  
Nan Hui Yu
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
External Magnetic Field ◽  
Field Strength ◽  
Internal Structure ◽  
Magnetic Field Strength ◽  
Particle Concentration ◽  
Microwave Frequency ◽  
Microwave Reflection ◽  
The Given

In this paper, experimental study of the microwave reflection behavior in MRF was carried out. The results showed that at the same frequency the microwave reflectivity of MRF decreased with the increasing of magnetic field strength; and with the increasing of particle concentration, microwave reflectivity decreased, monotonously. Under the given magnetic field, with the increasing of microwave frequency, it first decreased, there is a lowest point at 9.2GHz, and then it increased. Usually, it is considered that the change of internal structure of MRF under external magnetic field is the main reason for the regulation behavior of microwave reflectivity.

Effect of an external magnetic field on particle acceleration by a rotating black hole surrounded with quintessential energy

2018 ◽  
Vol 27 (08) ◽  
pp. 1850088 ◽  
Author(s):  
Sanjar Shaymatov ◽  
Bobomurat Ahmedov ◽  
Zdeněk Stuchlík ◽  
Ahmadjon Abdujabbarov
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Black Hole ◽  
External Magnetic Field ◽  
Field Intensity ◽  
Center Of Mass ◽  
Mass Energy ◽  
Intensity Parameter ◽  
Center Of Mass Energy ◽  
Spacetime Structure

We investigate particle motion and collisions in the vicinity of rotating black holes immersed in combined cosmological quintessential scalar field and external magnetic field. The quintessential dark-energy field governing the spacetime structure is characterized by the quintessential state parameter [Formula: see text] characterizing its equation of state, and the quintessential field-intensity parameter [Formula: see text] determining the static radius where the black hole attraction is just balanced by the quintessential repulsion. The magnetic field is assumed to be test field that is uniform close to the static radius, where the spacetime is nearly flat, being characterized by strength [Formula: see text] there. Deformations of the test magnetic field in vicinity of the black hole, caused by the Ricci non-flat spacetime structure are determined. General expression of the center-of-mass energy of the colliding charged or uncharged particles near the black hole is given and discussed in several special cases. In the case of nonrotating black holes, we discuss collisions of two particles freely falling from vicinity of the static radius, or one such a particle colliding with charged particle revolving at the innermost stable circular orbit. In the case of rotating black holes, we discuss briefly particles falling in the equatorial plane and colliding in close vicinity of the black hole horizon, concentrating attention to the interplay of the effects of the quintessential field and the external magnetic field. We demonstrate that the ultra-high center-of-mass energy can be obtained for black holes placed in an external magnetic field for an infinitesimally small quintessential field-intensity parameter [Formula: see text]; the center-of-mass energy decreases if the quintessential field-intensity parameter [Formula: see text] increases.

scholarly journals Dynamics of charged particles and magnetic dipoles around magnetized quasi-Schwarzschild black holes

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Bakhtiyor Narzilloev ◽  
Javlon Rayimbaev ◽  
Ahmadjon Abdujabbarov ◽  
Bobomurat Ahmedov ◽  
Cosimo Bambi
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Black Hole ◽  
External Magnetic Field ◽  
Coupling Parameter ◽  
Charged Particles ◽  
Kerr Black Hole ◽  
Rotation Parameter ◽  
Magnetic Dipoles ◽  
Deviation Parameter

AbstractIn the present paper, we have investigated the motion of charged particles together with magnetic dipoles to determine how well the spacetime deviation parameter $$\epsilon $$ ϵ and external uniform magnetic field can mimic the spin of a rotating Kerr black hole. Investigation of charged particle motion has shown that the deviation parameter $$\epsilon $$ ϵ in the absence of an external magnetic fields can mimic the rotation parameter of the Kerr spacetime up to $$a/M \approx 0.5$$ a / M ≈ 0.5 . The combination of an external magnetic field and deviation parameter can do even a better job mimicking the rotation parameter up to $$a/M\simeq 0.93$$ a / M ≃ 0.93 , which corresponds to the rapidly rotating case. Study of the dynamics of the magnetic dipoles around quasi-Schwarzschild black holes in the external magnetic field has shown that there are degeneracy values of the ISCO radius of test particles at $$\epsilon _{cr}>\epsilon \ge 0.35$$ ϵ cr > ϵ ≥ 0.35 which may lead to two different values of the innermost stable circular orbit (ISCO) radius. When the deviation parameter is in the range of $$\epsilon \in (-1,\ 1)$$ ϵ ∈ ( - 1 , 1 ) , it can mimic the spin of a rotating Kerr black hole in the range $$a/M \in (0.0537, \ 0.3952)$$ a / M ∈ ( 0.0537 , 0.3952 ) for magnetic dipoles with values of the magnetic coupling parameter $$\beta \in [-0.25,\ 0.25]$$ β ∈ [ - 0.25 , 0.25 ] in corotating orbits.

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