Weak Gravitational lensing from regular Bardeen black holes

TL;DR

This paper analyzes weak gravitational lensing effects caused by regular Bardeen black holes, focusing on how scalar charge influences image position and magnification, especially in cases with or without photon spheres.

Contribution

It introduces a detailed study of lensing by Bardeen black holes, highlighting the impact of scalar charge on image properties and the conditions for photon sphere disappearance.

Findings

Photon sphere presence depends on scalar charge parameter q.

Image parity differs between naked singularity and black hole cases.

Perturbative method effectively describes lensing parameters.

Abstract

In this article we study weak gravitational lensing of regular Bardeen black hole which has scalar charge $g$ and mass $m.$ We investigate the angular position and magnification of non-relativistic images in two cases depending on the presence or absence of photon sphere. Defining dimensionless charge parameter $q=\frac{g}{2m}$ we seek to disappear photon sphere in the case of $|q|>{24\sqrt5}/{125}$ for which the space time metric encounters strongly with naked singularities. We specify the basic parameters of lensing in terms of scalar charge by using the perturbative method and found that the parity of images is different in two cases: (a) The strongly naked singularities is present in the space time. (b) singularity of space time is weak or is eliminated (the black hole lens).