Observational signatures of wormholes with thin accretion disks

TL;DR

This paper numerically models the images of thin accretion disks around rotating wormholes, revealing distinctive observational signatures that could differentiate wormholes from black holes.

Contribution

It introduces a semi-analytic and a numerical ray-tracing method to simulate accretion disk images in wormhole backgrounds, highlighting unique observational features.

Findings

Wormhole accretion disk images differ significantly from black hole images.

Accretion disks can exist on both sides of a wormhole's throat.

Images from opposite sides of the throat can serve as evidence of wormhole geometries.

Abstract

We numerically construct images of thin accretion disks in rotating wormhole backgrounds, for the Kerr-like and the Teo class of wormholes. Our construction is illustrated by two methods, a semi-analytic scheme where separated null geodesic equations obtained by analytically integrating the second order equations once are used, as well as by a numerical ray-tracing method utilizing a fourth order Runge-Kutta algorithm. Our result shows dramatic differences between accretion disk images in wormhole backgrounds, compared to black hole ones, specifically because a wormhole can in principle have accretion disks on both sides of its throat. We establish the nature of the images if the observer and the disk are on two opposite sides of the throat, and show that these can provide conclusive observational evidence of wormhole geometries.