Weak Gravitational lensing by phantom black holes and phantom wormholes using the Gauss–Bonnet theorem

The Deflection Angle ◽

Bonnet Theorem ◽

Symmetric Spacetime

In this article, we demonstrate the weak gravitational lensing in the context of Bocharova-Bronnikove-Melnikov-Bekenstein (BBMB) black hole. To this desire, we derive the deflection angle of light in a plasma medium by BBMB black hole using the Gibbons and Werner method. First, we obtain the Gaussian optical curvature and implement the Gauss-Bonnet theorem to investigate the deflection angle for spherically symmetric spacetime of BBMB black hole. Moreover, we also analyze the graphical behavior of deflection angle by BBMB black hole in the presence of plasma medium.

Weak gravitational lensing by Bocharova–Bronnikov–Melnikov–Bekenstein black holes using Gauss–Bonnet theorem

The European Physical Journal Plus ◽

10.1140/epjp/s13360-020-00619-x ◽

2020 ◽

Vol 135 (7) ◽

Cited By ~ 1

Author(s):

Wajiha Javed ◽

Muhammad Bilal Khadim ◽

Ali Övgün

Keyword(s):

Black Holes ◽

Gravitational Lensing ◽

Weak Gravitational Lensing by Stringy Black Holes

10.20944/preprints201912.0045.v1 ◽

2019 ◽

Author(s):

Wajiha Javed ◽

Muhammad Bilal Khadim ◽

Jameela Abbas ◽

Ali Övgün

Keyword(s):

Black Holes ◽

Black Hole ◽

Gravitational Lensing ◽

Deflection Angle ◽

Plasma Medium ◽

Coupling Constant ◽

Hole Charge ◽

The Deflection Angle ◽

In this paper, we discuss the weak gravitational lensing in the context of stringy black holes. Initially, we examine the deflection angle of photon by charged stringy black hole. For this desire, we compute the Gaussian optical curvature and implement the Gauss-Bonnet theorem to investigate the deflection angle for spherically balanced spacetime of stringy black hole. We also analyze the influence of plasma medium in the weak gravitational lensing for stringy black hole. Moreover, the graphical impact of coupling constant $\alpha$, impact parameter $b$ , black hole charge $Q$ on deflection angle by charged stringy black hole has been studied in plasma as well as non-plasma medium.

Weak Deflection Angle of some Classes of non-linear Electrodynamics Black Holes via Gauss-Bonnet Theorem

10.20944/preprints202008.0370.v1 ◽

2020 ◽

Author(s):

Hasan El Moumni ◽

Karima Masmar ◽

Ali Övgün

Keyword(s):

Black Holes ◽

Black Hole ◽

Gravitational Lensing ◽

Deflection Angle ◽

Weak Field ◽

Leading Order ◽

Plasma Medium ◽

Non Linear ◽

The Deflection Angle ◽

In this paper, we study the gravitational lensing by some black hole classes within the non-linear electrodynamics in weak field limits. First, we calculate an optical geometry of the non-linear electrodynamics black hole then we use the Gauss-Bonnet theorem for finding deflection angle in weak field limits. The effect of non-linear electrodynamics on the deflection angle in leading order terms is studied. Furthermore, we discuss the effects of the plasma medium on the weak deflection angle.

Deflection Angle of Photon Through Dark Matter by Black Holes/Wormholes Using the Gauss-Bonnet Theorem

10.20944/preprints201903.0186.v1 ◽

2019 ◽

Author(s):

Ali Övgün

Keyword(s):

Dark Matter ◽

Gravitational Lensing ◽

Near Field ◽

Compact Objects ◽

Optical Geometry ◽

Field Information ◽

Bonnet Theorem ◽

Fish Eye ◽

Excellent Tool

Maxwell's fish eye has been known to be a perfect lens in optics. In this letter, using the Gibbons-Werner method, namely Gauss-Bonnet theorem on optical geometry of black hole, we extend the calculation of the weak gravitational lensing within the Maxwell's fisheye as a perfect lensing in medium composed of an isotropic refractive index that near-field information can be obtained from far-field distances. Moreover, these results provide an excellent tool to observe compact massive object by weak gravitational lensing within the dark matter medium and to understand the nature of the dark matter that may effect the gravitational waves. Moreover, we show that Gauss-Bonnet theorem is a global effect and this method can be used as a new tool on any optical geometry of compact objects in dark matter medium.

Weak deflection angle by asymptotically flat black holes in Horndeski theory using Gauss–Bonnet theorem

International Journal of Geometric Methods in Modern Physics ◽

10.1142/s0219887821500031 ◽

2020 ◽

Vol 18 (01) ◽

pp. 2150003

Author(s):

Wajiha Javed ◽

Jameela Abbas ◽

Yashmitha Kumaran ◽

Ali Övgün

Keyword(s):

Black Holes ◽

Gravitational Lensing ◽

Deflection Angle ◽

Weak Field ◽

Plasma Medium ◽

Asymptotically Flat ◽

Optical Geometry ◽

Principal Objective ◽

The Deflection Angle ◽

The principal objective of this project is to investigate the gravitational lensing by asymptotically flat black holes in the framework of Horndeski theory in weak field limits. To achieve this objective, we utilize the Gauss–Bonnet theorem to the optical geometry of asymptotically flat black holes and apply the Gibbons–Werner technique to achieve the deflection angle of photons in weak field limits. Subsequently, we manifest the influence of plasma medium on deflection of photons by asymptotically flat black holes in the context of Horndeski theory. We also examine the graphical impact of deflection angle on asymptotically flat black holes in the background of Horndeski theory in plasma medium as well as non-plasma medium.