Abstract
In this paper, we argue that one can calculate the weak deflection angle of light 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 by the black hole. Hence we demonstrate the observational viability via showing the effect of the dark matter on the weak deflection angle of light.
Highlights
Since the first photo of the Messier 87 black hole by Event Horizon Telescope, studying on black hole has been getting quite a lot of attention lately [1]
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
We have study the deflection angle for the EMDA black holes (BHs)
Summary
Since the first photo of the Messier 87 black hole by Event Horizon Telescope, studying on black hole has been getting quite a lot of attention lately [1]. In literature [27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48], a lot of researchers have studied the deflection angle of light for different types of BHs and wormholes by the following the formula of Gibbons and Werner which was proposed using the Gauss-Bonnet theorem:. Where Kis the Gaussian curvature and A∞ represents the infinite region of the surface It has been studied the weak gravitational lensing by wormholes and calculated the deflection angle via naked singularities and compare their results [49]. The main motivation of this paper is to study a conceivable extension of calculations of the bending angle of light for Einstein-Maxwell-Dilaton-Axion (EMDA) BH. CALCULATION OF DEFLECTION ANGLE BY BLACK HOLES IN EINSTEIN-MAXWELL-DILATON-AXION THEORY. Here Mrepresents the mass of BH and r0 is the parameter of dilaton-axion field
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
