The strong field gravitational lensing in the Schwarzschild black hole pierced by a cosmic string

TL;DR

This paper investigates how cosmic string tension influences strong field gravitational lensing around a Schwarzschild black hole, revealing that higher tension increases deflection angles while lower tension enhances time delays.

Contribution

It introduces the effect of cosmic string tension on gravitational lensing in the strong field limit around Schwarzschild black holes, a novel aspect not previously explored.

Findings

Deflection angle increases with cosmic string tension.

Time delay is more pronounced with weaker cosmic string tension.

Cosmic string tension significantly affects relativistic image properties.

Abstract

In this work the gravitational lensing in the strong field limit around the Schwarzschild black hole pierced by a cosmic string is studied. We find that the deflection angle and the time delay of the relativistic images depend on the tension of cosmic string. It is interesting that the deflection angle is greater when the tension of cosmic string is stronger. The time delay between two images is more obvious in the case of weaker tension.