# Planar Black holes and Entanglement Entropy in Analog Gravity Models

## TL;DR

This paper constructs explicit analog gravity models for planar black holes and introduces a holographic entanglement entropy concept applicable to a wide class of these models, expanding the known examples of such metrics.

## Contribution

It provides a method to realize planar black holes as analog metrics and extends the holographic entanglement entropy framework to more general conformal black-hole spacetimes.

## Key findings

- Explicit Lagrangian for analog black hole metrics
- Holographic entanglement entropy for planar black holes
- Broader class of known analog metrics

## Abstract

Via constructing an explicit Lagrangian for which the perturbation equations are analogues of a scalar field propagating in a planar black hole space-time, it is found that all planar black holes conformal to a Painlev\'e--Gullstrand type line element can be realized as analogue 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 analogue metrics.