The field of an accelerating black hole embedded in a magnetic universe

1984 ◽  
Vol 62 (9) ◽  
pp. 889-897
Author(s):  
K. D. Krori ◽  
Madhumita Barua
Keyword(s):  
Black Hole ◽  
Test Particles ◽  
Charged Test

In this paper, we investigate the field of an accelerating black hole embedded in a magnetic universe and present some interesting properties of the field with respect to the trapping of uncharged and charged test particles and their absorption into the black hole.

scholarly journals Supermassive black holes surrounded by dark matter modeled as anisotropic fluid: epicyclic oscillations and their fitting to observed QPOs

2021 ◽  
Vol 2021 (11) ◽  
pp. 059
Author(s):  
Z. Stuchlík ◽  
J. Vrba
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Anisotropic Fluid ◽  
Physical Parameters ◽  
Black Hole Spacetimes ◽  
Test Particles

Abstract Recently introduced exact solution of the Einstein gravity coupled minimally to an anisotropic fluid representing dark matter can well represent supermassive black holes in galactic nuclei with realistic distribution of dark matter around the black hole, given by the Hernquist-like density distribution. For these fluid-hairy black hole spacetimes, properties of the gravitational radiation, quasinormal ringing, and optical phenomena were studied, giving interesting results. Here, using the range of physical parameters of these spacetimes allowing for their relevance in astrophysics, we study the epicyclic oscillatory motion of test particles in these spacetimes. The frequencies of the orbital and epicyclic motion are applied in the epicyclic resonance variant of the geodesic model of quasiperiodic oscillations (QPOs) observed in active galactic nuclei to demonstrate the possibility to solve the cases where the standard vacuum black hole spacetimes are not allowing for explanation of the observed data. We demonstrate that the geodesic model can explain the QPOs observed in most of the active galactic nuclei for the fluid-hairy black holes with reasonable halo parameters.

scholarly journals Epicyclic oscillations in spinning particle motion around Kerr black hole applied in models fitting the quasi-periodic oscillations observed in microquasars and AGNs

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Misbah Shahzadi ◽  
Martin Kološ ◽  
Zdeněk Stuchlík ◽  
Yousaf Habib
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
High Frequency ◽  
Kerr Black Hole ◽  
Galactic Nuclei ◽  
Tidal Disruption ◽  
Periodic Oscillations ◽  
Spinning Particle ◽  
X Ray ◽  
Test Particles

AbstractThe study of the quasi-periodic oscillations (QPOs) of X-ray flux observed in the stellar-mass black hole (BH) binaries or quasars can provide a powerful tool for testing the phenomena occurring in strong gravity regime. We thus fit the data of QPOs observed in the well known microquasars as well as active galactic nuclei (AGNs) in the framework of the model of geodesic oscillations of Keplerian disks modified for the epicyclic oscillations of spinning test particles orbiting Kerr BHs. We show that the modified geodesic models of QPOs can explain the observational fixed data from the microquasars and AGNs but not for all sources. We perform a successful fitting of the high frequency QPOs models of epicyclic resonance and its variants, relativistic precession and its variants, tidal disruption, as well as warped disc models, and discuss the corresponding constraints of parameters of the model, which are the spin of the test particle, mass and rotation of the BH.

Bound orbits around modified Hayward black holes

2021 ◽  
Author(s):  
Bo Gao ◽  
Xue-Mei Deng
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Gravitational Field ◽  
Periodic Orbits ◽  
Kerr Black Hole ◽  
Periodic Oscillations ◽  
Test Particles ◽  
Spin Parameter ◽  
Bound Orbits

The neutral time-like particle’s bound orbits around modified Hayward black holes have been investigated. We find that both in the marginally bound orbits (MBO) and the innermost stable circular orbits (ISCO), the test particle’s radius and its angular momentum are all more sensitive to one of the parameters [Formula: see text]. Especially, modified Hayward black holes with [Formula: see text] could mimic the same ISCO radius around the Kerr black hole with the spin parameter up to [Formula: see text]. Small [Formula: see text] could mimic the ISCO of small-spinning test particles around Schwarzschild black holes. Meanwhile, rational (periodic) orbits around modified Hayward black holes have also been studied. The epicyclic frequencies of the quasi-circular motion around modified Hayward black holes are calculated and discussed with respect to the observed Quasi-periodic oscillations (QPOs) frequencies. Our results show that rational orbits around modified Hayward black holes have different values of the energy from the ones of Schwarzschild black holes. The epicyclic frequencies in modified Hayward black holes have different frequencies from Schwarzschild and Kerr ones. These might provide hints for distinguishing modified Hayward black holes from Schwarzschild and Kerr ones by using the dynamics of time-like particles around the strong gravitational field.

scholarly journals Particle motion around generic black holes coupled to non-linear electrodynamics

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
Jaroslav Vrba ◽  
Ahmadjon Abdujabbarov ◽  
Arman Tursunov ◽  
Bobomurat Ahmedov ◽  
Zdeněk Stuchlík
Keyword(s):  
Black Hole ◽  
Energy Conditions ◽  
Test Particles ◽  
Stable Circular Orbit ◽  
Spin Parameter ◽  
Non Linear ◽  
Innermost Stable Circular Orbit ◽  
Charge Parameter ◽  
Upper Estimate ◽  
Black Hole Solutions

Abstract We study spherically symmetric magnetically charged generic black hole solutions of general relativity coupled to non-linear electrodynamics (NED). For characteristic values of the generic spacetime parameters we give the position of horizons in dependence on the charge parameter, demonstrating separation of the black hole and no-horizon solutions, and possibility of existence of solutions containing three horizons. We show that null, weak and strong energy conditions are violated when the outer horizon is approaching the center. We study effective potentials for photons and massive test particles and location of circular photon orbits (CPO) and innermost stable circular orbit (ISCO). We show that the unstable photon orbit can become stable, leading to the possibility of photon capture which affects on silhouette of the central object. The position of ISCO approaches the horizon with increasing charge parameter q and the energy at ISCO decreases with increasing charge parameter. We investigate this phenomenon and summarize for a variety of the generic spacetime parameters the upper estimate on the spin parameter of the Kerr black which can be mimicked by the generic charged black hole solutions.

scholarly journals Dynamics of test particles around a Bardeen black hole surrounded by perfect fluid dark matter

2020 ◽  
Vol 102 (10) ◽  
Author(s):  
Bakhtiyor Narzilloev ◽  
Javlon Rayimbaev ◽  
Sanjar Shaymatov ◽  
Ahmadjon Abdujabbarov ◽  
Bobomurat Ahmedov ◽  
...  
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Perfect Fluid ◽  
Test Particles

CHARGED DILATONIC BLACK HOLE AND TEST PARTICLES

2000 ◽  
Vol 09 (05) ◽  
pp. 619-625
Author(s):  
SUBENOY CHAKRABORTY
Keyword(s):  
Black Hole ◽  
Detailed Analysis ◽  
Test Particles ◽  
Dilatonic Black Hole

We present a detailed analysis of the motion of test particles around a charged dilatonic black hole, using the Hamilton–Jacobi (HJ) formalism. We have considered test particles with various masses, electric charges and dilatonic charges and examine its behavior both in static and nonstatic cases.

scholarly journals Non-geodesic orbital and epicyclic frequencies in vicinity of slowly rotating magnetized neutron stars

2012 ◽  
Vol 8 (S290) ◽  
pp. 185-186
Author(s):  
Pavel Bakala ◽  
Martin Urbanec ◽  
Eva Šrámková ◽  
Zdeněk Stuchlík ◽  
Gabriel Török
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Equations Of Motion ◽  
Solution Of Equations ◽  
Test Particles ◽  
Perturbative Method ◽  
Relativistic Approach ◽  
Charged Test ◽  
The Magnetic Field

AbstractWe study non-geodesic corrections to the quasicircular motion of charged test particles in the field of magnetized slowly rotating neutron stars. The gravitational field is approximated by the Lense-Thirring geometry, the magnetic field is of the standard dipole character. Using a fully-relativistic approach we determine influence of the electromagnetic interaction (both attractive and repulsive) on the quasicircular motion. We focus on the behaviour of the orbital and epicyclic frequencies of the motion. Components of the four-velocity of the orbiting charged test particles are obtained by numerical solution of equations of motion, the epicyclic frequencies are obtained by using the standard perturbative method. The role of the combined effect of the neutron star magnetic field and its rotation in the character of the orbital and epicyclic frequencies is discussed.

scholarly journals ChargedQ-balls and boson stars and dynamics of charged test particles

2014 ◽  
Vol 89 (8) ◽  
Author(s):  
Yves Brihaye ◽  
Valeria Diemer ◽  
Betti Hartmann
Keyword(s):  
Boson Stars ◽  
Test Particles ◽  
Charged Test
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