Shadow images of Kerr-like wormholes

TL;DR

This paper studies the shadows cast by Kerr-like wormholes, analyzing how their shape and size are affected by spin, inclination, and deviation parameters, revealing distortions and size reductions compared to Kerr black holes.

Contribution

It provides the first detailed analysis of shadow shapes for Kerr-like wormholes, highlighting the effects of deviation parameters on observable features.

Findings

Shadow size decreases with increasing deviation parameter.

Spin and inclination angle cause distortions in the shadow shape.

Kerr spacetime can approximate the wormhole shadow far from the throat.

Abstract

Investigations of shadows of astrophysical entities constitute a major source of insight into the evolution of compact objects. Such effects depend on the nature of the compact object and arise on account of the strong gravitational lensing that casts a shadow on the bright background. We consider the Kerr-like wormhole spacetime (Phys.\ Rev.\ D 97:024040, 2018), which is a modification of the Kerr black hole that degenerates into wormholes for nonzero values of the deviation parameter $\lambda^2$. The results suggest that the Kerr spacetime can reproduce far away from the throat of the wormhole. We obtain the shapes of the shadow for the Kerr-like wormholes and discuss the effect of the spin $a$, the inclination angle $\theta_0$, and the deviation parameter $\lambda^2$ on the size and nature of the shadow. As a consequence, it is discovered that the shadow is distorted due to the spin as well as the deviation parameter and the radius of the shadow decreases with $\lambda^2$ if the ADM mass of the Kerr-like wormholes is considered.