Analogue black holes in relativistic BECs: Mimicking Killing and universal horizons

TL;DR

This paper explores how relativistic Bose-Einstein condensates can be used as analogue systems to simulate black hole horizons and universal horizons, providing a theoretical framework for studying complex gravitational phenomena.

Contribution

It introduces a method to mimic non-metric features like universal horizons in relativistic BECs using external Proca fields, advancing analogue gravity research.

Findings

Proposes coupling external fields to rBECs to simulate non-metric features.

Demonstrates how to mimic universal horizons relevant for superluminal modes.

Provides a theoretical basis for future experimental and numerical studies.

Abstract

Relativistic Bose-Einstein condensates (rBECs) have recently become a well-established system for analogue gravity. Indeed, while such relativistic systems cannot be yet realized experimentally, they provide an interesting framework for mimicking metrics for which no analogue is yet available, so paving the way for further theoretical and numerical explorations. In this vein, we here discuss black holes in rBECs and explore how their features relate to the bulk properties of the system. We then propose the coupling of external fields to the rBEC as a way to mimic non-metric features. In particular, we use a Proca field to simulate an aether field, as found in Einstein-Aether or Horava-Lifshitz gravity. This allows us to mimic a universal horizon, the causal barrier relevant for superluminal modes in these modified gravitational theories.