# Gravitational wave echoes from black hole area quantization

## TL;DR

This paper explores how quantized black hole horizon areas could produce observable gravitational wave echoes, offering a potential test for quantum gravity effects using current detectors.

## Contribution

It demonstrates that black hole area quantization may cause detectable distortions in gravitational wave signals, specifically in post-merger echoes.

## Key findings

- Detected characteristic frequency content in echoes consistent with area quantization
- Proposed gravitational wave echoes as a signature of quantum black hole horizons
- Suggests potential observability with current and future gravitational wave detectors

## Abstract

Gravitational-wave astronomy has the potential to substantially advance our knowledge of the cosmos, from the most powerful astrophysical engines to the initial stages of our universe. Gravitational waves also carry information about the nature of black holes. Here we investigate the potential of gravitational-wave detectors to test a proposal by Bekenstein and Mukhanov that the area of black hole horizons is quantized in units of the Planck area. Our results indicate that this quantization could have a potentially observable effect on the classical gravitational wave signals received by detectors. In particular, we find distorted gravitational-wave "echoes" in the post-merger waveform describing the inspiral and merger of two black holes. These echoes have a specific frequency content that is characteristic of black hole horizon area quantization.