# Planar Black Holes and Entanglement Entropy in Analog Gravity Models

## TL;DR

The paper shows how planar black holes can be modeled using analog gravity and introduces a new way to calculate entanglement entropy for these models.

## Contribution

The paper introduces a novel method to calculate holographic entanglement entropy for planar black holes using analog gravity.

## Key findings

- Planar black holes conformal to a Painlevé–Gullstrand-type line element can be realized as analog metrics.
- Holographic entanglement entropy is introduced for planar black-hole space–times with arbitrary conformal and blackening factors.

## Abstract

Via constructing an explicit Lagrangian for which the perturbation equations are analogs of a scalar field propagating in a planar black-hole space–time, it is found that all planar black holes conformal to a Painlevé–Gullstrand-type line element can be realized as analog metrics. We also introduce the concept of holographic entanglement entropy for planar black-hole space–times. This is valid for an arbitrary choice of conformal and blackening factor, thereby vastly extending the number of known examples of explicitly known analog metrics.