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Timelike holographic complexity

Mohsen Alishahiha

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Phys. Rev. D 114, 026033 – Published 27 July, 2026

DOI: https://doi.org/10.1103/4gsl-spj1

Abstract

Motivated by the pseudoentropy program, we study timelike subregion complexity within the holographic complexity=volume framework, extending previous spatial constructions to Lorentzian boundary intervals. For hyperbolic timelike regions in pure anti–de Sitter (AdS), we compute the enclosed bulk volume and show that, despite the Lorentzian embedding, the resulting complexity is purely real. We generalize the analysis to AdS black brane geometries, where extremal surfaces may either remain entirely outside the horizon or penetrate it, placing their timelike branch inside the black brane interior. In both configurations, the complexity exhibits the same universal UV divergences as the spacelike case, yet it receives no imaginary contribution—highlighting its causal and geometric origin. This reality stands in sharp contrast to the complex-valued pseudoentropy and indicates that holographic complexity retains a genuinely geometric, real character even under Lorentzian continuation.

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Phys. Rev. D 114, 026033– Published 27 July, 2026
  • Received 5 November 2025
  • Accepted 7 July 2026
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