Testing the black hole area law with Event Horizon Telescope

TL;DR

This paper tests Hawking's black hole area law using EHT observations of M87* and Sgr A*, finding current data consistent with the law and highlighting the potential for future observations to confirm or challenge it.

Contribution

It demonstrates the feasibility of testing the black hole area law with current EHT data and discusses how future high-precision observations could provide definitive tests.

Findings

Current EHT data are consistent with the black hole area law at 1 sigma confidence.

The variation fractions of horizon areas match theoretical predictions.

Future observations could decisively confirm or refute the area law.

Abstract

Hawking's black hole area theorem can be tested by monitoring the evolution of a single black hole over time. Using current imaging observations of two supermassive black holes M87* and Sgr A* from the Event Horizon Telescope (EHT), we find their horizon area variation fractions are consistent with the prediction of the black hole area law at the $1\,\sigma$ confidence level. We point out that whether the black hole area law is valid or not could be determined by future high precision EHT observations of Sgr A*.