Extending the model of rotating acoustic geometries to include non-vanishing solid-body rotation: quasibound spectra

TL;DR

This paper extends previous models of acoustic geometries to include solid-body rotation, analyzing quasibound states of massless excitations in vortex flows with analytical solutions.

Contribution

It introduces a theoretical extension to include solid-body rotation in acoustic black hole models and performs a spectral analysis using analytical solutions.

Findings

Aligned behavior with recent superfluid experiments

Analytical solutions for scalar wave equations in rotating flows

Extended understanding of vortex fluid dynamics

Abstract

In a very recent paper, we computed the quasibound states of massless acoustic excitations interacting with a new (effective) acoustic geometry with circulation. Notably, the behavior of this acoustic black hole aligns with the phenomenology observed in recent experiments that include superfluids. Such vortex fluid flow bundles exhibit solid-body rotation at length scales larger than the inter-vortex distance, which adds some complexity to the study of quantum fluid behaviour. To theoretically deal with this issue, we present an extension of our previous results by including a solid-body rotation term at the angular fluid velocity and then we perform a spectral study by using the analytical solutions for the scalar wave equation of motion.