Phase transitions, shadows, and microstructure of Kerr-Anti-de Sitter Black Holes from geometrothermodynamics
Ladino J.M. Romero-Figueroa C.E. Quevedo H.
September 2025Elsevier B.V.
Nuclear Physics B
2025#1018
Using the formalism of geometrothermodynamics, we investigate the phase-transition structure and microstructure of the Kerr-Anti-de Sitter black hole and show the relationship with its shadow structure. By treating the curvature radius as a thermodynamic variable, we ensure scaling consistency and model the system as quasi-homogeneous. In the canonical ensemble, we identify critical points and characterize both first- and second-order phase transitions independently of pressure. In the grand-canonical ensemble, we reveal a distinct phase structure, including the Hawking-Page transition. We derive analytical expressions for the Kerr-Anti-de Sitter black hole shadow and its critical parameters, using shadow thermodynamics to construct asymmetric shadow profiles that capture the phase-transition structure. Finally, we show that the singularities of the geometrothermodynamic curvature in the shadow align with divergences in thermodynamic response functions, confirming the correspondence between shadows, phase transitions, and microstructure.
Black Hole shadows , Geometrothermodynamics , Microstructure , Phase transitions
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Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico City, AP 70543, Mexico
Dipartimento di Fisica, Icra, Università di Roma “La Sapienza”, Roma, Italy
Al-Farabi Kazakh National University, Al-Farabi av. 71, Almaty, 050040, Kazakhstan
Instituto de Ciencias Nucleares
Dipartimento di Fisica
Al-Farabi Kazakh National University
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026