A Note on Black Hole Entropy and Wormhole Instabilities

• DOI: 10.48550/arxiv.2502.00769
• Publication Date: 2025-01-01
• Authors: Barbon, J. L. F.; Velasco-Aja, E.
• Keywords: High Energy Physics - Theory; High Energy Physics - Theory (hep-th); FOS: Physical sciences

21 pages, 6 figures; v2. additional references and improved discussion on the contours<br/>We discuss recent approaches to the computation of black hole entropies through semiclassical estimates of appropriate state overlaps, saturated by Euclidean wormhole configurations. We notice that the relevant saddle-point manifolds may exhibit instabilities, thereby compromising the interpretation of the Euclidean path integral as a tool for computing positive-definite inner products. We show that a proper treatment using a microcanonical formulation effectively addresses the puzzles posed by these instabilities.<br/>