Light deflection by charged wormholes in Einstein-Maxwell-dilaton theory

TL;DR

This paper investigates how electric, magnetic, and dilaton charges influence light deflection around charged wormholes in Einstein-Maxwell-dilaton theory, using optical geometry and confirming results with geodesic equations.

Contribution

It applies the Gibbons-Werner method to charged wormholes in Einstein-Maxwell-dilaton theory, providing new insights into how charges affect light deflection.

Findings

Deflection angle increases with electric and magnetic charges.

Deflection angle decreases with dilaton charge.

Gibbons-Werner method yields exact leading-order results.

Abstract

In this paper, we study the deflection of light by a class of charged wormholes within the context of the Einstein-Maxwell-dilaton theory. The primordial wormholes are predicted to exist in the early universe, where inflation driven by the dilaton field. We perform our analysis through optical geometry using the Gibbons-Werner method (GW), by adopting the Gauss-Bonnet theorem and the standard geodesics approach. We report an interesting result for the deflection angle in leading-order terms--namely, the deflection angle increases due to the electric charge $Q$ and the magnetic charge $P$, whereas it decreases due to the dilaton charge $\Sigma$. Finally, we confirm our findings by means of geodesics equations. Our computations show that the GW method gives an exact result in leading order terms.