2025/05/26 by A. Bonanno, Bonanno, Alfio, Samuele Silveravalle +1
Arts and Humanities · Physics and Astronomy · #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #History of Science and Medicine #Space Science and Extraterrestrial Life
paper · pdf · doi:10.48550/arxiv.2505.20360
openalex publication_date 2025/05/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A quantum ghost that destabilizes the Schwarzschild solution, transforming it into a naked singularity, may seem like a physicist's worst nightmare. However, we argue that this scenario represents the natural evolution of a black hole within a conservative high-energy gravity framework and may, in fact, be a desirable outcome. Quadratic curvature terms typically appear as corrections to the Einstein-Hilbert action at high energies; nonetheless, such theories are generally considered incomplete due to the presence of ghost particles at the quantum level, which can spoil vacuum stability. We argue that this instability can only be triggered at the final stages of black hole evaporation, starting a phase transition-like process that alters the nature of the spacetime, similarly to spontaneous scalarization. We propose that the endpoint is a stable, exotic naked singularity, possible only in modified gravity theories, and avoids some of the pathological features associated with standard naked singularities.