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AdS gravastar and its signatures from dual conformal field theory

Heng-Yu Chen1, Yasuaki Hikida2,*, and Yasutaka Koga2

  • *Contact author: yasuaki.hikida@oit.ac.jp
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Phys. Rev. Research 8, 023065 – Published 21 April, 2026

DOI: https://doi.org/10.1103/6cbs-c9n2

Abstract

Quantum gravity effects are expected to resolve the black hole singularity and the effects may deform the region near but outside the horizon. Applying AdS/CFT correspondence, we see their signatures from the viewpoint of dual conformal field theory. As a regularized geometry, we consider AdS gravastar constructed by gluing AdS-Schwarzschild and de Sitter spacetime. The retarded Green's functions of dual conformal field theory have bulk-cone singularities associated with null trajectories in the bulk and we obtain the singularities specific to a horizonless geometry. We also observe echoes coming from waves reflected behind the photon sphere. The existence of echoes implies the modification of geometry inside the photon sphere.

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Phys. Rev. Research 8, 023065– Published 21 April, 2026
  • Received 8 December 2025
  • Accepted 27 March 2026
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