scholarly journals Shadow and weak deflection angle of extended uncertainty principle black hole surrounded with dark matter

2021 ◽  
pp. 168722
Author(s):  
Reggie C. Pantig ◽  
Paul K. Yu ◽  
Emmanuel T. Rodulfo ◽  
Ali Övgün
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Uncertainty Principle ◽  
Deflection Angle ◽  
Extended Uncertainty

scholarly journals Deflection of light by a rotating black hole surrounded by “quintessence”

2020 ◽  
Vol 35 (26) ◽  
pp. 2050155 ◽  
Author(s):  
Prateek Sharma ◽  
Hemwati Nandan ◽  
Radouane Gannouji ◽  
Rashmi Uniyal ◽  
Amare Abebe
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Deflection Angle ◽  
Energy Condition ◽  
Additional Parameter ◽  
Deviation Angle ◽  
Extremal Case ◽  
Rotating Black Hole ◽  
State Formula ◽  
Kerr Space

We present a detailed analysis of a rotating black hole surrounded by “quintessence.” This solution represents a fluid with a constant equation of state, [Formula: see text], which can for example describe an effective warm dark matter fluid around a black hole. We clarify the conditions for the existence of such a solution and study its structure by analyzing the existence of horizons as well as the extremal case. We show that the deflection angle produced by the black hole depends on the parameters [Formula: see text] which need to obey the condition [Formula: see text] because of the weak energy condition, where [Formula: see text] is an additional parameter describing the hair of the black hole. In this context, we found that for [Formula: see text] (consistent with warm dark matter) and [Formula: see text], the deviation angle is larger than that in the Kerr space–time for direct and retrograde orbits. We also derive an exact solution in the case of [Formula: see text].

scholarly journals Effect of the Dilaton Field on Deflection Angle of Massive Photons by Black Holes in Einstein-Maxwell-Dilaton-Axion Theory

2019 ◽  
Author(s):  
Wajiha Javed ◽  
Rimsha Babar ◽  
Ali Övgün
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Deflection Angle ◽  
Weak Field ◽  
Dilaton Field ◽  
Plasma Medium ◽  
The Deflection Angle ◽  
Bonnet Theorem ◽  
Massive Photons

In this paper, we argue that one can calculate the weak deflection angle in the background of Einstein-Maxwell-Dilaton-Axion black hole using the Gauss-Bonnet theorem. To support this, the optical geometry of the black hole with the Gibbons-Werner method are used to obtain the deflection angle of light in the weak field limits. Moreover, we investigate the effect of a plasma medium on deflection of light for a given black hole. Because of dilaton and axion are one of the candidate of the dark matter, it can give us a hint on observation of dark matter which is supported the black hole. Hence we demonstrate the observational viability via showing the effect of the dark matter on the weak deflection angle.

Thermodynamic effects of Bardeen black hole surrounded by perfect fluid dark matter under general uncertainty principle

2021 ◽  
Author(s):  
Zhenxiong Nie ◽  
Yun Liu ◽  
Juhua Chen ◽  
Yongjiu Wang
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Perfect Fluid ◽  
Uncertainty Principle ◽  
Generalized Uncertainty Principle ◽  
Thermodynamic Quantities ◽  
Logarithmic Term ◽  
Corrected Entropy ◽  
Thermodynamic Effects ◽  
Thermodynamic Variables

Abstract In this paper, the thermodynamics of Bardeen black hole surrounded by perfect fluid dark matter is investigated. We calculate the analytical expresses of corresponding thermodynamic variables, e.g. the Hawking temperature, entropy of the black hole. In addition, we derive the heat capacity to analyze the thermal stability of the black hole. We also compute the rate of emission in terms of photons through tunneling. By numerical method, an obvious phase transition behavior is found. Furthermore, according to the general uncertainty principle, we study the quantum corrections to these thermodynamic quantities and obtain the quantum-corrected entropy containing the logarithmic term. At last, we investigate the effects of the magnetic charge g, the dark matter parameter k and the generalized uncertainty principle parameter α on the thermodynamics of Bardeen black hole surrounded by perfect fluid dark matter under general uncertainty principle.

Probing an Extended Uncertainty Principle black hole with gravitational lensings

2019 ◽  
Vol 34 (20) ◽  
pp. 1950152 ◽  
Author(s):  
Xu Lu ◽  
Yi Xie
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Uncertainty Principle ◽  
Gravitational Lensing ◽  
Galactic Center ◽  
Apparent Size ◽  
Position Uncertainty ◽  
Fundamental Scale ◽  
Sgr A ◽  
Extended Uncertainty

We study signals of the weak and strong deflection gravitational lensings by an Extended Uncertainty Principle (EUP) black hole, which is based on a modified Heisenberg relation with an additional correction of position-uncertainty. Gravitational lensing observables, including positions, magnifications and differential time delays between lensed images, are obtained in both scenarios and analyzed for the supermassive black holes (SMBHs) in the Galactic Center (Sgr A*) and M87. We find that, for Sgr A*, measurements on the separation between the primary and secondary images in the weak deflection lensing and the apparent size of the photon sphere in the strong deflection lensing are two feasible ways to constrain EUP, imposing comparable lower bounds on the fundamental scale of EUP as [Formula: see text][Formula: see text]1010 m. For the SMBH in M87, measurements on strong deflection lensing observables are only available and they can give a much bigger lower bound as [Formula: see text][Formula: see text]1013 m. These results might provide hints for probing EUP black holes by gravitational lensings.

scholarly journals PLANCK-SIZE BLACK HOLE REMNANTS AS DARK MATTER

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1047-1054 ◽  
Author(s):  
PISIN CHEN
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Early Universe ◽  
Uncertainty Principle ◽  
Generalized Uncertainty Principle ◽  
Inflation Model ◽  
Interesting Candidate ◽  
Hybrid Inflation ◽  
Black Hole Remnant

While there exist various candidates, the nature of dark matter remains unresolved. Recently it was argued that the generalized uncertainty principle (GUP) may prevent a black hole from evaporating completely, and as a result there should exist a Planck-size black hole remnant (BHR) at the end of its evaporation. If a sufficient amount of small black holes can be produced in the early universe, then the resultant BHRs can be an interesting candidate for DM. We demonstrate that this is indeed the case for the hybrid inflation model. By assuming BHR as DM, our notion imposes a constraint on the hybrid inflation potential. We show that such a constraint is not so fine-tuned. Possible observational signatures are briefly discussed.

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