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Coarse graining holographic black holes in higher curvature gravity

Qiongyu Qi*

  • *Contact author: qiongyu.qi@student.uva.nl
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Phys. Rev. D 114, 046022 – Published 24 August, 2026

DOI: https://doi.org/10.1103/tb8p-rxkg

Abstract

We consider the holographic description of the dynamical black hole entropy in f(R) higher curvature gravity which proposed by Hollands-Wald-Zhang. On the bulk side, we show that the coarse-grained entropy (outer entropy) of a generalized marginally trapped surface corresponds precisely to the Wald entropy associated with this surface. To get this result, we first formulate the AdS/CFT correspondence in the Einstein frame and derive the correspondence between the von Neumann entropy in the Einstein frame and the f(R) frame. This facilitates the derivation of the correspondence between the two outer entropies in the two frames. Furthermore, we directly derive a focusing theorem associated with generalized expansion in f(R) gravity. We then formulate how to construct the stationary null hypersurface for the generalized expansion and the junction condition to glue a hypersurface in f(R) gravity. Combining these results, we directly derive the expression for the outer entropy in the f(R) frame and identify its holographic dual.

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Phys. Rev. D 114, 046022– Published 24 August, 2026
  • Received 20 March 2026
  • Accepted 27 July 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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