Resonant transmission of scalar waves through rotating traversable wormhole

TL;DR

This study investigates how scalar waves resonate in rotating traversable wormholes, revealing sharp resonance peaks that could serve as distinctive observational signatures differentiating wormholes from black holes.

Contribution

It extends previous static wormhole resonance analyses to rotating cases, showing rotation amplifies resonance features and characterizes wormhole signatures.

Findings

Resonance peaks are identified as Breit-Wigner-type in the spectrum.

Rotation enhances the strength of the resonance peaks.

Resonant features persist in rotating wormhole backgrounds.

Abstract

The viability of traversable wormholes as exotic compact objects requires the identification of signatures that distinguish them from other compact objects. Given recent advances in observing rotating black hole signatures, identifying characteristic imprints that reflect the absence of an event horizon and the presence of a throat structure is of considerable significance. Motivated by this, in the present work, we analyze the propagation of a massless scalar field in a rotating traversable wormhole spacetime described by Teo's class of solutions. We numerically compute the transmission (greybody) factor and the corresponding absorption spectrum across a broad range of frequencies. The spectrum exhibits a series of sharp peaks in the amplitudes, which we identify as Breit-Wigner-type resonances. The emergence of such peaks can be attributed to the scalar modes temporarily trapped within the potential well formed by barriers on either side of the throat. These resonant features, previously identified in static wormhole backgrounds, persist in the rotating case. In particular, for Teo's class of wormholes, we find that rotation enhances the strength of the resonances. Overall, our results demonstrate the role of rotation in shaping the resonance effect and indicate these features as characteristic signatures of wormhole geometries.