Observational Optical Constraints of Regular Black Holes

Jafarzade, Khadije; Zangeneh, M. Kord

doi:10.2139/ssrn.4181207

Cited by 6 publications

(1 citation statement)

References 69 publications

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“…With this in view, gravitational lensing has since been widely used as a key element to provide convincing comparisons and explanation for arbitrary theories of gravity. In this respect, a large amount of work has been implemented extensively to study gravitational lensing in recent years [69][70][71][72][73][74][75][76][77][78][79]. Furthermore, the gravitational lensing effects were considered powerful tools for testing the Weyl and bumblebee theories of gravity as well as the Lorentz invariance violation in bumblebee gravity [80,81].…”

Section: Introductionmentioning

confidence: 99%

A regular MOG black hole’s impact on shadows and gravitational weak lensing in the presence of a quintessence field

Al-Badawi,

Shaymatov,

Alloqulov

et al. 2024

Commun. Theor. Phys.

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We investigate the impact of the modified gravity (MOG) field and the quintessence scalar field on horizon evolution, black hole (BH) shadow and the weak gravitational lensing around a static spherically symmetric BH. We first begin to write the BH metric associated with the MOG parameter and quintessence scalar field. We then determine the BH shadow and obtain numerical solutions for the photon sphere and shadow radius. We show that the MOG ($\alpha$) and the quintessence ($c$) parameters have a significant impact on BH shadow and photon sphere. Based on the analysis, we further show that the combined effects of the MOG parameter and quintessential field can increase the values of BH shadow and photon sphere radii. We also obtain constraints on the BH parameters by applying the observational data of Sgr A$^{\star}$ and M87$^{\star}$. Finally, we consider the weak deflection angle of BH within the context of the Gauss-Bonnet theorem (GBT) and show that the combined effects of the MOG and quintessence parameters do make the value of the deflection angle grow, referring to remarkable property being in well agreement with the physical meaning of both parameters that can maintain the strong gravitational field in the surrounding environment of BH.

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Section: Introductionmentioning

confidence: 99%

A regular MOG black hole’s impact on shadows and gravitational weak lensing in the presence of a quintessence field

Al-Badawi,

Shaymatov,

Alloqulov

et al. 2024

Commun. Theor. Phys.

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Observational appearances of a f(R) global monopole black hole illuminated by various accretions

2021

Eur. Phys. J. C

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In this paper, we explore three simple models of accretions on a global monopole black hole in f(R) theory, and numerically study the corresponding observational appearances as seen by an observer located at the asymptotic infinity and the certain region out of black hole. For the thin-disk accretion, the results here show that the brighter lensing ring and the darker photon ring that around black hole shadow, always make a small contribution and a negligible contribution to total observed intensity respectively. While, the direct emission of disk contributes a dominant part, and the size of shadow always depends on the disk’s location. For the static and infalling spherical accretions, it turns out that the radiuses of the shadows and photon spheres are always same for both accretions, which implies that the boundary of shadow represents the signature of the spacetime geometry in this case. However, we also find that the brightness of shadow in infalling accretion is darker than that in static case since the Doppler effect is taken into account. In addition, the effect of the global monopole parameter $$\eta $$ η and f(R) parameter $$\psi _0$$ ψ 0 on observational appearances of black hole are clearly emphasized throughout of this paper. Finally, we conclude that black hole shadows and the related rings with some different observable features can be used for us to distinguish black holes from different gravity theories and set the upper limits to the f(R) parameter $$\psi _0$$ ψ 0 .

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Einstein and Møller Energy-Momentum Distributions for the Static Regular Simpson–Visser Space-Time

et al. 2021

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Energy-momentum localization for the four-dimensional static and spherically symmetric, regular Simpson–Visser black hole solution is studied by use of the Einstein and Møller energy-momentum complexes. According to the particular values of the parameter of the metric, the static Simpson–Visser solution can possibly describe the Schwarzschild black hole solution, a regular black hole solution with a one-way spacelike throat, a one-way wormhole solution with an extremal null throat, or a traversable wormhole solution of the Morris–Thorne type. In both prescriptions it is found that all the momenta vanish, and the energy distribution depends on the mass m, the radial coordinate r, and the parameter a of the Simpson–Visser metric. Several limiting cases of the results obtained are discussed, while the possibility of astrophysically relevant applications to gravitational lensing issues is pointed out.

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Observational Optical Constraints of Regular Black Holes

Cited by 6 publications

References 69 publications

A regular MOG black hole’s impact on shadows and gravitational weak lensing in the presence of a quintessence field

A regular MOG black hole’s impact on shadows and gravitational weak lensing in the presence of a quintessence field

Observational appearances of a f(R) global monopole black hole illuminated by various accretions

Einstein and Møller Energy-Momentum Distributions for the Static Regular Simpson–Visser Space-Time

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