Bounds on gravitational brane couplings and tomography in AdS3 black hole microstates

We study information theoretic properties of planar black hole microstates in 2 + 1 dimensional asymptotically anti-de Sitter spacetime, modeled by black holes with an end-of-the-world brane behind the horizon. The von Neumann entropy of sufficiently large subregions in the dual CFT exhibits a time-dependent phase, which from a doublyholographic perspective corresponds to the appearance of quantum extremal islands in the brane description. Considering the case where dilaton gravity is added to the brane, we show that tuning the associated couplings affects the propagation of information in the dual CFT state. By requiring that information theoretic bounds on the growth of entanglement entropy are satisfied in the dual CFT, we can place bounds on the allowed values of the couplings on the brane. Furthermore, we initiate the study of brane tomography, by showing how subleading corrections to the entanglement velocity can be used to learn about the properties of the brane as well as any gravitational dynamics localized on it.

Automated summary

This study investigates the information theoretic properties of planar black hole microstates in 2 + 1 dimensional asymptotically anti-de Sitter spacetime. The von Neumann entropy of subregions in the dual CFT shows a time-dependent phase, corresponding to the appearance of quantum extremal islands in the brane description. The addition of dilaton gravity on the brane affects the propagation of information in the dual CFT state. Information theoretic bounds on the growth of entanglement entropy place constraints on the allowed values of the couplings on the brane. Furthermore, the study explores how subleading corrections to the entanglement velocity can provide information about the properties of the brane and any localized gravitational dynamics.