Violation of cosmic censorship in Einstein-Maxwell-Scalar models with fractional coupling

Abstract

The weak cosmic censorship conjecture plays a foundational role in classical gravity by asserting that spacetime singularities are generically hidden behind event horizons. In this work, we explore its robustness in the Einstein-Maxwell-Scalar theory with fractional coupling by studying both static black hole solutions and their fully nonlinear dynamical evolution. We identify a class of scalarized black holes that develop negative energy density near the event horizon, indicating violations of the classical energy conditions. Numerical evolutions of perturbed configurations reveal that sufficiently strong fractional coupling drives rapid curvature growth and geometric degeneration in the near-horizon region, accompanied by persistent negative energy density. While the simulations do not resolve the ultimate end state, the observed dynamics consistently point toward a weakening of the horizon-supporting structure and are suggestive of incipient naked singularity formation. These results uncover a classical mechanism through which fractional coupling can challenge the validity of the weak cosmic censorship conjecture in asymptotically flat spacetimes.

13 pages, 19 figures, accepted for publication in EPJC

References in corpus (20)

• Test bodies and naked singularities: is the self-force the cosmic censor?
• Gedanken Experiments to Destroy a Black Hole II: Kerr-Newman Black Holes Cannot be Over-Charged or Over-Spun
• Black hole spontaneous scalarisation with a positive cosmological constant
• Critical phenomena in dynamical scalarization of charged black hole
• Weak cosmic censorship conjecture in Einstein-Born-Infeld black holes
• Dynamical transitions in scalarization and descalarization through black hole accretion
• Nonperturbative gedanken experiments in Einstein-dilaton-Gauss-Bonnet gravity: nonlinear transitions and tests of the cosmic censorship beyond General Relativity
• Dynamical scalarization in Einstein-Maxwell-dilaton theory
• What is the fate of Hawking evaporation in gravity theories with higher curvature terms?
• Dynamical spontaneous scalarization in Einstein-Maxwell-scalar theory
• Dynamical spontaneous scalarization in Einstein-Maxwell-scalar models in anti-de Sitter spacetime
• Electromagnetic dual Einstein-Maxwell-scalar models
• Weak Cosmic Censorship Conjecture Cannot be Violated in Gedanken Experiments
• Overcharging a multi black hole system and cosmic censorship
• Test the Weak Cosmic Supervision Conjecture in Dark Matter-Black Hole System
• The Weak Cosmic Censorship Conjecture in Hairy Kerr Black Holes
• Hawking radiation may violate the Penrose cosmic censorship conjecture
• Extraction of energy from a black hole in Einstein-Maxwell-scalar theory
• Exploring the cosmic censorship conjecture with a Gauss-Bonnet sector
• Stability of Extremal Black Holes and Weak Cosmic Censorship Conjecture in Kiselev Spacetime