Tidal Love numbers of analogue black holes

TL;DR

This paper explores the tidal Love numbers of acoustic black holes across various dimensions, revealing similarities with higher-dimensional general relativistic black holes, including vanishing responses and ladder symmetries.

Contribution

It extends the study of tidal Love numbers to acoustic black holes, demonstrating their properties and symmetries in different dimensions, paralleling gravitational black hole behavior.

Findings

Tidal Love numbers exhibit logarithmic running with distance.

Vanishing tidal response occurs for specific multipole moments.

Ladder symmetries explain the vanishing responses.

Abstract

Tidal Love numbers quantify the conservative static response of compact objects to external tidal fields, and are found to vanish exactly for asymptotically flat black holes in four-dimensional general relativity. Many aspects of the physics of black holes have an analogue in the theory of supersonic acoustic flows, including the existence of an event horizon and associated phenomena, such as quasinormal modes and superradiance. In this paper, we investigate the tidal Love numbers of acoustic black holes in different number of dimensions. We find that they exhibit a number of similar properties as higher-dimensional general relativistic black holes, such as logarithmic running with radial distance, and vanishing tidal response for special multipole moments. We show that the latter is a consequence of ladder symmetries, analogous to those identified for black holes.