Gravitational lensing effect in traversable wormholes

TL;DR

This paper investigates the gravitational lensing effects in charged traversable wormholes, focusing on photon sphere conditions and their implications for detecting wormhole geometries through lensing rings.

Contribution

It derives conditions for photon sphere existence at and outside the wormhole throat, considering different redshift functions, advancing understanding of lensing signatures of wormholes.

Findings

Photon spheres can exist at or outside the wormhole throat.

Multiple photon spheres can lead to concentric lensing rings.

Results may aid in detecting wormholes via gravitational lensing.

Abstract

The present paper is intended for studying the effect of strong gravitational lensing in the context of charged wormhole. To study this effect, the conditions determining the existence of photon spheres at and outside the throat are obtained. The necessary and sufficient conditions for the existence of photon spheres at or outside the throat of the charged wormhole is derived. Furthermore, photon spheres are investigated in three cases for three different forms of redshift function. These three cases include the existence of effective photon spheres (i) at the throat, (ii) outside the throat and (iii) both at and outside the throat. Consequently, these provide the information about the formation of infinite number of concentric rings and may lead to the detection of wormhole geometries.