Harvesting mutual information from BTZ black hole spacetime

TL;DR

This paper studies how two detectors can extract mutual information from a BTZ black hole spacetime, revealing that extreme Hawking radiation prevents mutual information harvesting near the event horizon.

Contribution

It provides the first analysis of mutual information harvesting in BTZ black hole spacetime, highlighting the impact of Hawking radiation on information extraction.

Findings

Mutual information is zero only at the event horizon.

Hawking radiation inhibits mutual information harvesting.

Communication effects are negligible in the setup.

Abstract

We investigate the correlation harvesting protocol for mutual information between two Unruh-DeWitt detectors in a static BTZ black hole spacetime. Here, the effects coming from communication and change in proper separation of the detectors are set to be negligible so that only a black hole affects the extracted mutual information. We find that, unlike the entanglement harvesting scenario, harvested mutual information is zero only when a detector reaches an event horizon, and that although the Hawking effect and gravitational redshift both affect the extraction of mutual information, it is extreme Hawking radiation that inhibits the detectors from harvesting.