Strong Gravitational Lensing by Bardeen Black Hole in Cloud of Strings

TL;DR

This paper studies how Bardeen black holes in a cloud of strings cause strong gravitational lensing, analyzing the effects of the CoS parameter and comparing with astrophysical observations of SgrA* and M87*.

Contribution

It introduces a detailed analysis of gravitational lensing by Bardeen black holes in a cloud of strings, including strong deflection coefficients and observational constraints.

Findings

Calculated strong deflection coefficients for various CoS parameters.

Derived magnification and Einstein rings for specific black holes.

Constrained CoS parameter using EHT observations of SgrA* and M87*.

Abstract

We investigate the gravitational lensing by Bardeen black hole in cloud of strings (CoS) in strong field limit. The effect of CoS parameter $b$ has been outlined in comparison with Bardeen black hole lens. The strong deflection limit coefficients are determined in terms of impact parameter for various values of CoS parameter. We obtain magnification of relativistic images and determine relativistic Einstein rings by using the parameters of two astrophysical black hole lenses $SgrA^{*}$ and $M87^{*}$. We constrain CoS parameter of Bardeen black hole using EHT observations for these black holes.