Lensing observables: Massless dyonic vis-\`a-vis Ellis wormhole

TL;DR

This paper compares gravitational lensing signatures of massless dyonic wormholes and Ellis wormholes, revealing similarities and differences that could impact astrophysical observations and theoretical understanding.

Contribution

It applies the parametric post-Newtonian method to two different wormhole solutions, highlighting qualitative similarities and quantitative differences in lensing observables.

Findings

Lensing signatures can be similar across different wormhole solutions.

Quantitative differences depend on parameter values.

An unexpected divergence in differential time delay correction was observed.

Abstract

Stable massless wormholes are theoretically interesting in their own right as well as for astrophysical applications, especially as galactic halo objects. Therefore, the study of gravitational lensing observables for such objects is of importance, and we do here by applying the parametric post-Newtonian method of Keeton and Petters to massless dyonic charged wormholes of the Einstein-Maxwell-Dilaton field theory and to the massless Ellis wormhole of the Einstein minimally coupled scalar field theory. The paper exemplifies how the lensing signatures of two different solutions belonging to two different theories could be qualitatively similar from the observational point of view. Quantitative differences appear depending on the parameter values. Surprisingly, there appears an unexpected divergence in the correction to differential time delay, which seems to call for a review of its original derivation.