# On Distinguishability of Black Hole Microstates

## TL;DR

This paper investigates how well black hole microstates can be distinguished using measurements on subregions of the dual CFT, revealing a size threshold for distinguishability and comparing with holographic reconstruction models.

## Contribution

It introduces a method using Holevo information to quantify microstate distinguishability in AdS/CFT and identifies the subregion size needed for effective discrimination.

## Key findings

- Microstates are indistinguishable below a certain subregion size.
- Perfect distinguishability occurs before the entire Cauchy surface is covered.
- Results align with entanglement wedge reconstruction and tensor network models.

## Abstract

We use the Holevo information to estimate distinguishability of microstates of a black hole in anti-de Sitter space by measurements one can perform on a subregion of a Cauchy surface of the dual conformal field theory. We find that microstates are not distinguishable at all until the subregion reaches a certain size and that perfect distinguishability can be achieved before the subregion covers the entire Cauchy surface. We will compare our results with expectations from the entanglement wedge reconstruction, tensor network models, and the bit threads interpretation of the Ryu-Takayanagi formula.