Effect of the hair on deflection angle by asymptotically flat black holes in Einstein-Maxwell-dilaton theory

W Javed,J Abbas,A Övgün

doi:10.1103/physrevd.100.044052

Abstract

In this paper, we are interested in a model of exact asymptotically flat charged hairy black holes in the background of dilaton potential. We study the weak gravitational lensing in the spacetime of hairy black hole in Einstein-Maxwell theory with a non-minimally coupled dilaton and its non-trivial potential. In doing so, we use the optical geometry of the flat charged hairy black hole for some range of parameter $\gamma$. For this purpose, by using Gauss-Bonnet theorem, we obtain the deflection angle of photon in a spherically symmetric and asymptotically flat spacetime. Moreover, we also investigate the impact of plasma medium on weak gravitational lensing by asymptotically flat charged hairy black hole with a dilaton potential. Our analytically analyses show the effect of the hair on the deflection angle in weak field limits.

Highlights

At the darkest points in the universe, their boundaries perilous and invisible, space warps
We try to understand the effect of the hair on deflection angle by asymptotically flat black holes in Einstein-Maxwell-dilaton (EMD) theory, where is derived from a string theory at low energy limits [11]
This paper is organized as follows: In section 2, we review some basic concepts about asymptotically flat hairy BH

Summary

INTRODUCTION

At the darkest points in the universe, their boundaries perilous and invisible, space warps. ∂D i where κ is the geodesic curvature for ∂D : {t} → D and θi is the exterior angle with ith vertex Following this approach, global symmetric lenses are considered to be Riemannian metric manifolds, which are geodesic spatial light rays. We calculate the Gaussian optical curvature K to find the asymptotic bending angle which can be calculated as follows [14]:. Note that this equation is an exact result for the deflection angle. It will be interesting to see the form of the deflection angle in the case of non-asymptotically Euclidian metrics This method has been applied in various papers for different types of spacetimes [15–43]. The last section comprises of concluding remarks and results obtained from graphical analysis

ASYMPTOTICALLY FLAT BLACK HOLES IN EINSTEIN-MAXWELL-DILATON THEORY

Photon lensing in a plasma medium

NEW ASYMPTOTICALLY FLAT BLACK HOLES IN EINSTEIN-MAXWELL-DILATON THEORY

Q2 p2π 32 b2

CONCLUSION