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

Author(s):  
Muhammad Rizwan ◽  
Tooba Feroze

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.

2007 ◽  
Vol 16 (08) ◽  
pp. 1369-1379
Author(s):  
R. KAYA

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.


2019 ◽  
Vol 487 (4) ◽  
pp. 4965-4984 ◽  
Author(s):  
J J Zanazzi ◽  
Dong Lai

ABSTRACT After the tidal disruption event (TDE) of a star around a supermassive black hole (SMBH), the bound stellar debris rapidly forms an accretion disc. If the accretion disc is not aligned with the spinning SMBH’s equatorial plane, the disc will be driven into Lense–Thirring precession around the SMBH’s spin axis, possibly affecting the TDE’s light curve. We carry out an eigenmode analysis of such a disc to understand how the disc’s warp structure, precession, and inclination evolution are influenced by the disc’s and SMBH’s properties. We find an oscillatory warp may develop as a result of strong non-Keplarian motion near the SMBH. The global disc precession frequency matches the Lense–Thirring precession frequency of a rigid disc around a spinning black hole within a factor of a few when the disc’s accretion rate is high, but deviates significantly at low accretion rates. Viscosity aligns the disc with the SMBH’s equatorial plane over time-scales of days to years, depending on the disc’s accretion rate, viscosity, and SMBH’s mass. We also examine the effect of fallback material on the warp evolution of TDE discs, and find that the fallback torque aligns the TDE disc with the SMBH’s equatorial plane in a few to tens of days for the parameter space investigated. Our results place constraints on models of TDE emission which rely on the changing disc orientation with respect to the line of sight to explain observations.


2019 ◽  
Vol 35 (10) ◽  
pp. 2050061
Author(s):  
Z. Luo ◽  
X. G. Lan

It is suggested that the dispersion relation might be corrected at higher energy scales and lead to the deformed Hamilton–Jacobi equation. In this paper, we use the correction to investigate the fermion tunneling radiation for Demianski–Newman black hole spacetime, and the result shows that the corresponding Hawking temperature and the black hole entropy are related to the angular parameters of the black hole coordinates.


1989 ◽  
Vol 67 (5) ◽  
pp. 501-504
Author(s):  
K. D. Krori ◽  
Ranjana Choudhury ◽  
J. C. Sarmah

In this paper we show that in the Kerr–Newman–de Sitter space–time material particles may move in stable orbits in the equatorial plane (θ = π/2) of the Kerr–Newman black hole.


2020 ◽  
Vol 30 ◽  
pp. 100648 ◽  
Author(s):  
Sanjar Shaymatov ◽  
Jaroslav Vrba ◽  
Daniele Malafarina ◽  
Bobomurat Ahmedov ◽  
Zdeněk Stuchlík

2005 ◽  
Vol 20 (14) ◽  
pp. 1077-1085 ◽  
Author(s):  
MARICEL AGOP ◽  
EUGEN RADU ◽  
REINOUD SLAGTER

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.


2003 ◽  
Vol 18 (12) ◽  
pp. 2153-2157 ◽  
Author(s):  
A. A. Bytsenko ◽  
Yu. P. Goncharov

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.


2002 ◽  
Vol 17 (34) ◽  
pp. 2277-2281 ◽  
Author(s):  
EUGEN RADU

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.


2011 ◽  
Vol 26 (16) ◽  
pp. 1221-1230 ◽  
Author(s):  
HIROMI SUZUKI

Previously we investigated the cosmic wiggly strings in (3+1)-dimensional Schwarzschild, Reissner–Nordström and Kerr black holes. As an extension, the solutions in (3+1)-dimensional axially symmetric charged rotating black hole are investigated. The solution for the wiggly string exhibits open strings lying along the circular orbit in the equatorial plane outside horizon.


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