# Black hole acoustics in the minimal geometric deformation of a de Laval nozzle

## TL;DR

This paper explores the analogy between sound waves in a de Laval nozzle and quasinormal modes of brane-world black holes, providing a laboratory method to study higher-dimensional gravity effects.

## Contribution

It establishes a correspondence between acoustic perturbations in a de Laval nozzle and black hole quasinormal modes in a brane-world scenario, linking laboratory acoustics to higher-dimensional gravity.

## Key findings

- Sound wave patterns in the nozzle reflect black hole quasinormal modes.
- The shape of the nozzle can be derived from brane-world models.
- Laboratory acoustic data can inform about 5D bulk Weyl fluid properties.

## Abstract

The correspondence between sound waves, in a de Laval propelling nozzle, and quasinormal modes emitted by brane-world black holes deformed by a 5D bulk Weyl fluid are here explored and scrutinised. The analysis of sound waves patterns in a de Laval nozzle at a laboratory, reciprocally, is here shown to provide relevant data about the 5D bulk Weyl fluid and its on-brane projection, comprised by the minimal geometrically deformed compact stellar distribution on the brane. Acoustic perturbations of the gas fluid flow in the de Laval nozzle are proved to coincide to the quasinormal modes of black holes solutions deformed by the 5D Weyl fluid, in the geometric deformation procedure. Hence, in a phenomenological E\"otv\"os-Friedmann fluid brane-world model, the realistic shape of a de Laval nozzle is derived and its consequences studied.