Correspondence between quasinormal modes and the shadow radius in a wormhole spacetime

TL;DR

This study investigates the relationship between quasinormal modes and shadow radius in wormhole spacetimes, including static and rotating models, and assesses their potential to mimic black holes based on observational data.

Contribution

It extends the correspondence between QNMs and shadow radius to rotating wormholes and explores their observational signatures in comparison to black holes.

Findings

The shadow radius varies with rotation and model parameters.

A reflecting point exists where the shadow radius changes behavior.

Constraints on wormhole throat radius from EHT data for M87.

Abstract

In this paper we study the correspondence between the real part of quasinormal modes (QNMs) and the shadow radius in a wormhole spacetime. Firstly we consider the above correspondence in a static and spherically symmetric wormhole spacetime and then explore this correspondence numerically by considering different wormhole models having specific redshift functions. To this end, we generalize this correspondence to the rotation wormhole spacetime and calculate the typical shadow radius of the rotating wormhole when viewed from the equatorial plane. We argue that due to the rotation and depending on the specific model, the typical shadow radius can increase or decrease and a reflecting point exists. Finally, we discuss whether a wormhole can mimic the black hole due to it's shadow. In the light of the EHT data, we find the upper and lower limits of the wormhole throat radius in the galactic center M87.