Role of the scalar field in gravitational lensing

TL;DR

This paper investigates how a scalar field influences gravitational lensing, revealing unique phenomena like multiple Einstein rings and images, especially at high scalar charge to mass ratios, expanding understanding of exotic lensing objects.

Contribution

It introduces a static, circularly symmetric scalar field lens model and explores its distinctive lensing features compared to Schwarzschild lenses.

Findings

Existence of multiple Einstein rings and a radial critical curve.

Formation of two or four images depending on parameters.

Potential to detect three images for distant sources.

Abstract

A static and circularly symmetric lens characterized by mass and scalar charge parameters is constructed. For the small values of the scalar charge to the mass ratio, the gravitational lensing is qualitatively similar to the case of the Schwarzschild lens; however, for large values of this ratio the lensing characteristics are significantly different. The main features are the existence of two or nil Einstein ring(s) and a radial critical curve, formation of two or four images and possibility of detecting three images near the lens for sources located at relatively large angular positions. Such a novel lens may also be treated as a naked singularity lens.