Review article on black hole information and macroscopic entanglement

Black Hole Information, Replica Wormholes, and Macroscopic Entanglement

Xavier Calmet, Stephen D.H. Hsu

In this invited review, we discuss the evaporation of a black hole, with emphasis on the resulting macroscopically distinct patterns of Hawking radiation. The density matrix of this radiation can approach a pure final state in the form of a highly entangled macroscopic superposition state. We note that this exact property is exhibited in replica wormhole calculations, and also in quantum hair effects on Hawking radiation amplitudes. Finally, we revisit the information paradox (Mathur's theorem and firewalls), showing that it can be resolved by macroscopic entanglement.

https://arxiv.org/abs/2412.07807

We just posted this brief review article on arXiv. It is based on our earlier work, especially in https://arxiv.org/abs/2404.02331

We were asked to write a pedagogical review by a journal editor who enjoyed my recent talk at Caltech. (Click through for slides, etc.)

I don’t have recorded video from the Caltech seminar, but here is a similar talk I gave at the Chinese Academy of Science in Beijing.