Can wormholes and black holes be distinguished by magnification?

TL;DR

This paper investigates whether wormholes and black holes can be distinguished by their gravitational lensing magnification effects using the rotational Simpson-Visser metric, revealing distinct peak patterns in magnification.

Contribution

It introduces a finite distance analysis of light deflection in the RSV metric and compares magnification patterns of different compact objects, highlighting observable differences.

Findings

Ellis-Bronnikov wormhole shows single magnification peak

Kerr black hole exhibits one to three peaks

Milky Way's central black hole has multiple peaks, but unobservable from Earth

Abstract

The magnification effect of wormholes and black holes has been extensively researched. It is crucial to provide a finite distance analysis to understand this magnification phenomenon better. In this article, the rotational Simpson-Visser metric (RSV) is chosen as the focus of research. By calculating the deflection of light in RSV metric, we determine the resulting magnification effect, then applied the RSV metric to specific examples such as the Ellis-Bronnikov wormhole, Schwarzschild black hole, and Kerr black hole (or wormhole) to analyze the magnification. We find that Ellis-Bronnikov wormhole only has single magnification peaks, while Kerr black hole has one to three magnification peaks. In addition, the article's findings suggest that the lensing effect of the Central Black Hole of the Milky Way Galaxy exhibits magnification of multiple peaks. However, it should be noted that these effects are not observable from Earth.