Strong lensing of a regular black hole with an electrodynamics source

Manna, Tuhina; Rahaman, Farook; Molla, Sabiruddin; Bhadra, Jhumpa; Shah, Hasrat Hussain

doi:10.1007/s10714-018-2375-3

Cited by 10 publications

(4 citation statements)

References 58 publications

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“…In the strong field limit of arbitrary statics and spherically symmetric (SSS) spacetime, Bozza [43] developed a general method to calculate the deflection angle for lightrays and showed that it always diverges logarithmically as ln(x − x 0 ) where x 0 is the closest approach of the ray. Many authors successfully calculated the deflection angles in the strong field limit for particular spacetimes using this method [41,[44][45][46][47]. However, from an observational point of view, all the light bending and GLs seen up to now are in the weak field limit, i.e., with small deflection angles.…”

Section: Introductionmentioning

confidence: 99%

The perturbative approach for the weak deflection angle

Jia

2020

Eur. Phys. J. C

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Both null and timelike rays experience trajectory bending in a gravitational field. In this work, we systematically develop a perturbative method to compute the deflection angle of rays with general velocity v in arbitrary static and spherically symmetric spacetimes and in equatorial plane of arbitrary static and axisymmetric spacetimes. We show that the expansion in the large closest approach x0 limit depends on the asymptotic behavior of the metric functions only, and the generated integrand is always integrable, resulting in a deflection angle in a series form of either x0 or b, the impact parameter. Using this method, the deflection angles as series of both x0 and b are found in Schwarzschild, Reissner-Nordström and Kerr-Newman spacetimes to 17-th, 15-th and 6-th orders respectively, for both lightrays and particles with general velocity. The effects of the impact parameter, velocity and other parameters of the spacatimes are briefly analyzed. Moreover, we show that for spacetimes whose metric functions are only asymptotically known, the deflection angle in the weak field limit can also be calculated. Furthermore, it is shown that the deflection angle in general static and spherically symmetric spacetime and equatorial plane of static and axisymmetric spacetime to the lowest non-trivial order, depends only on the impact parameter, velocity of the particle, and the effective ADM mass of the spacetime but not on other parameters such as charge or angular momentum. These deflection angles are used in an exact gravitational lensing equation and the corresponding apparent angles of the images of the source are also solved perturbatively.

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Section: Introductionmentioning

confidence: 99%

The perturbative approach for the weak deflection angle

Jia

2020

Eur. Phys. J. C

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“…Strong deflection case on the other hand, is used for another problems: for example, for investigations of so-called relativistic images. To this end, we wish to point out the strong gravitational lensing for the Schwarzschild black hole [5,6], then extended to the Reissner-Nordstr öm black hole [7,8], regular black holes [9], and wormholes [10][11][12][13], while the investigations of so-called relativistic images see also Refs. [14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Distinguishing rotating naked singularities from Kerr-like wormholes by their deflection angles of massive particles

et al. 2019

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We study the gravitational deflection of relativistic massive particles by Janis-Newman-Winicour (JNW) spacetimes (also known as a rotating source with a surface-like naked singularity), and a rotating Kerr-like wormholes. Based on the recent article [K. Jusufi, Phys.Rev. D 98, 064017 (2018)], we extend some of these results by exploring the effects of naked singularity and Kerr-like objects on the deflection of particles. We start by introducing coordinate transformation leading to an isotropic line element which gives the refraction index of light for the corresponding optical medias. On the other hand, the refraction index for massive particles is found by considering those particles as a de Broglie wave packets. To this end, we apply the Gauss-Bonnet theorem to the isotropic optical metrics to find the deflection angles. Our analysis shows that, in the case of the JNW spacetime the deflection angle is affected by the parameter 0 < γ < 1, similarly, we find that the deformation parameter λ affects the deflection angle in the case of Kerr-like wormholes. In addition to that, we presented a detailed analysis of the deflection angle by means of the Hamilton-Jacobi equation that lead to the same results. As a special case of our results the deflection angle of light is recovered. Finally, we point out that the deflection of particles by Kerr-like wormholes is stronger compared to JNW spacetime, in particular this difference can be used to shed some light from observational point of view in order to distinguish the two spacetimes.

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“…Similarly, micro GL is worked on the bases of strong GL, in which the image separation is too small to be resolved. Gravitational lensing is processed in different space times in different ways [12][13][14][15][16][17]. Moreover, in past years, many studies have related GL with the Gauss-Bonnet theorem (GBT) after Gibbons and Werner's conformation of the useful method for calculating the bending angle of BHs that shows asymptotic behaviour [18], which is given as:…”

Section: Introductionmentioning

confidence: 99%

Weak Deflection Angle and Greybody Bound of Magnetized Regular Black Hole

2022

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In this paper, we examine the weak deflection angle and greybody bound for a magnetized regular black hole. For this purpose, we apply the Gauss–Bonnet theorem on the black hole and obtain the deflection angle in plasma and non-plasma mediums. Moreover, we investigate graphically the effect of impact parameter on the deflection angle for regular black hole in both mediums. We examine that the deflection angle goes to infinity when the impact parameter approaches zero. We also observe that the deflection angle shows negative behaviour at q=0.6 and q=2.09, but at 0.6<q<2.09, the angle shows positive behaviour. Furthermore, we study the rigorous bound phenomenon of the greybody factor in the background for a magnetized regular black hole. Later, we analyse the graphical behaviour of greybody bound with respect to different values of ω and observe that, at small values of ω, the bound increases, but for large values, the bound decreases. After that, we examine that, when we put G=1, l=0 and q=0, all results for the magnetized regular black hole solution reduce into results of the Schwarzschild black hole solution.

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Strong lensing of a regular black hole with an electrodynamics source

Cited by 10 publications

References 58 publications

The perturbative approach for the weak deflection angle

The perturbative approach for the weak deflection angle

Distinguishing rotating naked singularities from Kerr-like wormholes by their deflection angles of massive particles

Weak Deflection Angle and Greybody Bound of Magnetized Regular Black Hole

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