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Detecting black hole microstates

Vijay Balasubramanian1,2,3,*, William K. L. Chan1,†, and Chitraang Murdia1,‡

  • *Contact author: vijay@physics.upenn.edu
  • †Contact author: chanwill@sas.upenn.edu
  • ‡Contact author: murdia@sas.upenn.edu
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Phys. Rev. D 113, 046020 – Published 25 February, 2026

DOI: https://doi.org/10.1103/yqts-ybrd

Abstract

We demonstrate that the Euclidean two-point function of an appropriately chosen probe operator can detect the microstate of an asymptotically AdS black hole. This detection, which requires a tuned, state-dependent choice of probe, is the result of a new gravitational saddle, which dominates over the usual saddles. The gravitational result can be explicitly reproduced in the dual boundary CFT if we assume the eigenstate thermalization hypothesis. We also discuss a binary search protocol to detect the black hole microstate from a candidate list.

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Outline

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Phys. Rev. D 113, 046020– Published 25 February, 2026
  • Received 19 November 2025
  • Accepted 5 February 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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