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

scholarly journals Dynamics and epicyclic motions of particles around the Schwarzschild–de Sitter black hole in perfect fluid dark matter

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Javlon Rayimbaev ◽  
Sanjar Shaymatov ◽  
Mubasher Jamil
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Perfect Fluid ◽  
Matter Field ◽  
De Sitter ◽  
Circular Orbits ◽  
Test Particles ◽  
Remarkable Result ◽  
The Impact ◽  
Twin Peak

AbstractIn this paper, we investigate circular orbits for test particles around the Schwarzschild–de Sitter (dS) black hole surrounded by perfect fluid dark matter. We determine the region of circular orbits bounded by innermost and outermost stable circular orbits. We show that the impact of the perfect fluid dark matter shrinks the region where circular orbits can exist as the values of both innermost and outermost stable circular orbits decrease. We find that for specific lower and upper values of the dark matter parameter there exist double matching values for inner and outermost stable circular orbits. It turns out that the gravitational attraction due to the dark matter contribution dominates over cosmological repulsion. This gives rise to a remarkable result in the Schwarzschild–de Sitter black hole surrounded by dark matter field in contrast to the Schwarzschild–de Sitter metric. Finally, we study epicyclic motion and its frequencies with their applications to twin peak quasi-periodic oscillations (QPOs) for various models. We find the corresponding values of the black hole parameters which could best fit and explain the observed twin peak QPO object GRS 1915+109 from microquasars.

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 Shadow cast by a rotating and nonlinear magnetic-charged black hole in perfect fluid dark matter

2021 ◽  
pp. 2150112
Author(s):  
Tian-Chi Ma ◽  
He-Xu Zhang ◽  
Peng-Zhang He ◽  
Hao-Ran Zhang ◽  
Yuan Chen ◽  
...  
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Perfect Fluid ◽  
Emission Rate ◽  
Magnetic Charge ◽  
Spherically Symmetric ◽  
Intensity Parameter ◽  
Shadow Cast ◽  
Sgr A ◽  
Charge Formula

In this paper, we derived an exact solution of the spherically symmetric Hayward black hole surrounded by perfect fluid dark matter (PFDM). By applying the Newman–Janis algorithm, we generalized it to the corresponding rotating black hole. Then, we studied the shadows of rotating Hayward black hole in PFDM. The apparent shape of the shadow depends upon the black hole spin [Formula: see text], the magnetic charge [Formula: see text] and the PFDM intensity parameter [Formula: see text]. The shadow is a perfect circle in the non-rotating case [Formula: see text] and a deformed one in the rotating case [Formula: see text]. For a fixed value of [Formula: see text], the size of the shadow increases with the increasing [Formula: see text], but decreases with the increasing [Formula: see text]. We further investigated the black hole emission rate. We found that the emission rate decreases with the increasing [Formula: see text] (or [Formula: see text]) and the peak of the emission shifts to lower frequency. Finally, we discussed the observational prospects corresponding to the supermassive black hole Sgr A[Formula: see text] at the center of the Milky Way.

scholarly journals Testing the weak cosmic censorship conjecture for a Reissner–Nordström–de Sitter black hole surrounded by perfect fluid dark matter

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Sanjar Shaymatov ◽  
Bobomurat Ahmedov ◽  
Mubasher Jamil
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Cosmological Constant ◽  
Perfect Fluid ◽  
Linear Order ◽  
Cosmic Censorship ◽  
Cosmological Parameter ◽  
De Sitter ◽  
Non Linear ◽  
Cosmic Censorship Conjecture

AbstractIn this paper, we test the weak cosmic censorship conjecture (WCCC) for the Reissner–Nordström–de Sitter (RN-dS) black hole surrounded by perfect fluid dark matter. We consider a spherically symmetric perturbation on deriving linear and non-linear order perturbation inequalities by applying a new version of gedanken experiments well accepted from the work of Sorce and Wald. Contrary to the well-known result that the Reissner–Nordström (RN) black hole could be overcharged under linear order particle accretion it is hereby shown that the same black hole in perfect fluid dark matter with cosmological parameter cannot be overcharged. Considering a realistic scenario in which black holes cannot be considered to be in vacuum we investigate the contribution of dark matter and cosmological constant in the overcharging process of an electrically charged black hole. We demonstrate that the black hole can be overcharged only when two fields induced by dark matter and cosmological parameter are completely balanced. Further we present a remarkable result that a black hole cannot be overcharged beyond a certain threshold limit for which the effect arising from the cosmological constant dominates over the effect by the perfect fluid dark matter. Thus even for a linear accretion process, the black hole cannot always be overcharged and hence obeys the WCCC in general. This result would continue to be fulfilled for non-linear order accretion.

scholarly journals Regular (Bardeen) black hole surrounded by perfect fluid dark matter

2021 ◽  
Author(s):  
He-Xu Zhang ◽  
Yuan Chen ◽  
Tian-Chi Ma ◽  
Peng-Zhang He ◽  
Jian-Bo Deng
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Perfect Fluid

scholarly journals Rotating black hole shadow in perfect fluid dark matter

2018 ◽  
Vol 2018 (12) ◽  
pp. 040-040 ◽  
Author(s):  
Xian Hou ◽  
Zhaoyi Xu ◽  
Jiancheng Wang
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Perfect Fluid ◽  
Rotating Black Hole
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