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Theorem Status and Open Censorship Problems

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Cosmic censorship is a family of mathematical statements, not one binary proposition. A theorem occupies a cell labeled by matter model, symmetry, asymptotics, initial-data topology, genericity, maximal development, and extension or visibility regularity. A counterexample in one cell need not touch another. The purpose of a status page is therefore to expose the matrix and the missing implications, not to announce that “censorship is true” or “false.”

Evidence cutoff: 2026-08-12. Peer-reviewed theorems are distinguished from conditional results, linear evidence, and current preprints. Later revisions or new exterior-to-interior results can change individual cells without changing the formulation axes.

Required background. Analysis for Mathematical Relativity supplies topology and genericity, while the Einstein equation supplies the MGHD.

Helpful background. Causality and Global Structure supplies weak/strong censorship definitions; PDEs and Green Functions for Gravitation supplies data and weak-solution classes; and Black-Hole Geometry and Mechanics supplies model interiors.

Write a censorship statement as

(E,S,A,D,T,G,C).(\mathcal E,\mathcal S,\mathcal A, \mathcal D,\mathcal T,\mathcal G, \mathcal C).

E\mathcal E is the field system, S\mathcal S the symmetry restriction, A\mathcal A the asymptotics and boundary condition, D\mathcal D the data class, T\mathcal T its topology, G\mathcal G the genericity quantifier, and C\mathcal C the conclusion. For weak censorship, C\mathcal C may be completeness of a constructed I+\mathscr I^+. For strong censorship it is inextendibility in C0C^0, Lipschitz, Christoffel-L2L^2, C2C^2, or another specified class.

Two results conflict only if all coordinates match and their conclusions are logical negations. Different regularity or topology is not a technical caveat; it defines another conjecture.

For sufficiently regular constraint-satisfying Einstein data, local well-posedness and the Choquet-Bruhat–Geroch construction give an MGHD unique up to an isometry fixing the embedded data. This is the starting theorem, not SCC: the MGHD can still admit a proper extension in which the initial hypersurface is no longer Cauchy Choquet-Bruhat–Geroch 1969, theorem and pp. 329–335.

Spherical Einstein–scalar weak censorship

Section titled “Spherical Einstein–scalar weak censorship”

Christodoulou proves that naked outcomes in his spherical massless-scalar BV∩L1BV\cap L^1 characteristic class have a positive-codimension instability in a precise two-direction sense Christodoulou 1999, Theorem 4.1, pp. 214–216. This is strong evidence—and a rigorous instability theorem—for that WCC formulation. It is not a theorem for unrestricted smooth vacuum Cauchy data.

An and Tan’s 2024 v1 preprint claims a charged analogue for the spherical Einstein–Maxwell–charged-complex-scalar system. In the exact characteristic class BV([0,∞),dv)∩L1((0,∞),dv/v)BV([0,\infty),dv)\cap L^1((0,\infty),dv/v), data outside an exceptional set have complete future null infinity, and every exceptional datum lies in a complex two-dimensional transverse family containing no other exceptional datum An–Tan 2024, Theorem 1.1 and Remark 1, pp. 2–3, and Theorem 9.1, p. 136. The claim is symmetry reduced and unrefereed; its transversality statement is not an unrestricted probability or open-density theorem.

Spherical Einstein–Maxwell–scalar strong censorship

Section titled “Spherical Einstein–Maxwell–scalar strong censorship”

For admissible two-ended asymptotically flat spherical Cauchy data, the MGHD has a nonempty Cauchy horizon and is C0C^0 future extendible, so C0C^0 SCC fails in that model. Luk and Oh prove that a generic class—open in a weighted C1C^1 topology and dense in a weighted C∞C^\infty topology—has the exterior lower tail that forces C2C^2 future inextendibility Luk–Oh 2019 I, Theorems 1.8–1.10 and Luk–Oh 2019 II, Theorems 1.1 and 1.5. Therefore the C0C^0 and C2C^2 formulations have opposite verdicts in the same symmetry-reduced matter class.

Nonlinear T3T^3 Gowdy theorems establish C2C^2 inextendibility on precise open/dense sets within the two-Killing-field vacuum class Isenberg 2015, §§4–5, pp. 7–11. They demonstrate an SCC mechanism for compact cosmology, but the Gowdy subspace is not open in the full vacuum constraint set.

Dafermos and Luk prove that appropriate nonsymmetric spacelike Cauchy data already inside a black hole and approaching subextremal Kerr near timelike infinity develop a nontrivial Cauchy horizon with a continuous metric extension Dafermos–Luk 2025, Theorems 4.2 and 4.24, pp. 50–52 and 64–65 of the open manuscript. This is a peer-reviewed interior C0C^0-stability theorem. It is conditional on the stated interior asymptotics rather than derived from unrestricted exterior Cauchy data.

The following results prevent old blanket summaries.

Rough spherical naked solutions. A May 2026 preprint claims nonlinear open- set stability of continuously self-similar spherical Einstein–scalar naked solutions in a localized C1,αC^{1,\alpha}-adapted Hölder topology Zheng 2026, Definitions 2.7 and 2.11 and Theorem 3.1, arXiv v1. This challenges a WCC formulation in that rough topology while leaving Christodoulou’s BV perturbation statement intact.

Structured characteristic naked solutions. The vacuum exterior construction has a v1 companion interior: the glued spacetime is the maximal development of a complete asymptotically flat characteristic cone and has incomplete future null infinity Shlapentokh-Rothman 2022, Theorem 1.3, pp. 5–6. Its initial data are arbitrarily regular angularly but only C1,sC^{1,s} in the null direction Shlapentokh-Rothman 2022, Remark 1.2, pp. 5–6. A July 2026 v1 preprint also constructs nonspherical Einstein–scalar solutions from structured κ\kappa-self-similar incoming data and small outgoing null perturbations, with incomplete I+\mathscr I^+ and a quantified scalar-field obstruction at the singular inner Cauchy horizon An–Wu 2026, Theorem 1.3, pp. 3–4. These are existence results for named characteristic classes, not stable smooth complete-Cauchy-data counterexamples.

Full-subextremal exterior Kerr stability. Hintz’s v2 preprint, revised 2026-08-03, claims nonlinear exterior stability for small smooth vacuum perturbations of every fixed subextremal Kerr background. The simple theorem uses data equal to Kerr outside a compact set; the precise theorem permits a finite partial-polyhomogeneous expansion with a controlled faster-decaying remainder. It supplies the decay needed by the Dafermos–Luk interior theorem for that structured class and states the resulting interior consequence Hintz 2026, Theorem 1.1 and consequence (1), pp. 2–3, and Theorem 13.1, pp. 318–319, arXiv v2. This is a full-subextremal theorem claim, but it remains an unrefereed preprint whose proof uses two same-author companion preprints as black-box inputs. It is not independent confirmation or a result for arbitrary asymptotically flat data.

Vacuum Kerr Lipschitz obstruction. A March 2026 preprint claims curvature blowup and Lipschitz inextendibility near the Kerr Cauchy horizon for interior data satisfying a precise nonlinear Price-law lower estimate Gurriaran 2026, eqs. (4.2.8)–(4.2.9) and Theorem 4.5.1, pp. 51–52 and 55–56, arXiv v2. The lower estimate is expected to be generic but is an assumption in that result. Hintz’s exterior decay theorem does not automatically prove this nonvanishing lower law: a generic higher-regularity SCC result must match the two hypotheses in compatible gauges and data spaces and verify the current preprint dependencies.

de Sitter spectral competition. Neutral scalar modes on fixed Kerr–Newman–de Sitter backgrounds can have β>1/2\beta>1/2 in a near-extremal charged region, permitting finite local scalar energy at the Cauchy horizon, whereas other parameter ranges possess obstructing modes Davey–Dias–Sola Gil 2024, §§2.3.3 and 5. This is linear test-field evidence, not nonlinear Einstein–Maxwell SCC.

These positions are not a two-sided debate with one winner. They occupy different topology, regularity, system, and proof-status cells.

QuestionEvidence through cutoffMissing step
WCC for unrestricted 3+1 vacuum asymptotically flat dataUnresolved open conjectureLarge-data global exterior classification and a precise genericity theorem
WCC for spherical massless scalar in Christodoulou’s BV classExceptional naked data are unstable in specified perturbation directionsTranslation to other regularities or nonsymmetric data
WCC for spherical Einstein–Maxwell–charged scalar in BV∩L1(dv/v)BV\cap L^1(dv/v) characteristic dataPositive-codimension exceptional-set theorem claimed in a 2024 v1 preprintPeer review, other topologies, and nonsymmetric data
WCC for rough self-similar spherical scalar dataOpen-set naked stability claimed in a 2026 preprintIndependent review, other topologies, nonsymmetric perturbations
Structured characteristic naked solutionsComplete-cone vacuum existence and nonspherical Einstein–scalar existence are claimed in v1 preprintsOpen stability, smooth complete Cauchy formation, and genericity in an unrestricted data space
C0C^0 SCC for two-ended spherical Einstein–Maxwell–scalarFalse in the theorem’s data class: continuous Cauchy-horizon extensions existOne-ended collapse and other matter classes are separate
C2C^2 SCC in the same two-ended spherical classProved generically by Luk–OhRemoval of symmetry and transfer to vacuum Kerr
C0C^0 behavior near subextremal Kerr Cauchy horizonsContinuous interior extension is peer-reviewed; Hintz v2 claims the exterior-to-interior consequence for a structured small-data classIndependent verification, broader asymptotic classes, and genericity transfer
Lipschitz SCC near Kerr i+i_+Claimed conditionally on a nonlinear Price law in 2026Prove the nonvanishing lower law generically and match it to the exterior theorem’s gauge and data class
KNdS nonlinear SCCNot settled by existing scalar spectral scansCoupled nonlinear gravito-electromagnetic interior and genericity theorem
AdS WCC/SCCFormulation depends on timelike-boundary conditionGlobal large-data theorem for each named boundary problem

The matrix makes one key point visible: Hintz v2 now supplies a full-subextremal exterior theorem claim and a Dafermos–Luk consequence for its structured data class, but this does not by itself finish SCC. A higher-regularity generic theorem still needs the exact nonvanishing tail asymptotics required by the interior blowup result, compatible gauges and data spaces, and independent verification of the preprint proof chain.

  1. Constraints to exterior. Construct an open or residual class of general large Cauchy data and determine whether its visible exterior is complete.
  2. Exterior to event horizon. Prove sharp upper and nonvanishing lower Price laws, including the perturbation sectors relevant to the nonlinear metric.
  3. Event horizon to Cauchy horizon. Propagate those bounds through the full rotating interior and classify C0C^0, Lipschitz, weak, and C2C^2 behavior.
  4. Genericity transfer. Show that the exceptional set identified by a tail coefficient has the declared topology or codimension in the original constraint manifold.
  5. Other asymptotics. Repeat the formulation with de Sitter observer components or an explicit AdS boundary condition rather than importing the asymptotically flat statement.

Van de Moortel’s current survey organizes the modern PDE results and these interfaces Van de Moortel 2025, §§2–7. Its status synthesis is a guide to primary theorems, not a replacement for their hypotheses.

A peer-reviewed theorem resolving one of these questions, a correction or withdrawal of a 2026 preprint, or a counterexample in a specified model and data class could change the comparison. The remaining cases are open questions; they do not imply a universal conclusion about cosmic censorship.

Consider the sentence: “Continuous Cauchy horizons are stable, so strong cosmic censorship is false.” Give the strongest defensible replacement using current theorems.

Solution

In the two-ended spherically symmetric Einstein–Maxwell–real-scalar data class, MGHDs possess continuously extendible Cauchy horizons, so the C0C^0 inextendibility formulation is false there; nevertheless generic data are C2C^2 future inextendible. For nonsymmetric vacuum data satisfying Kerr-like interior asymptotics, continuous extension across a nontrivial horizon segment is proved. Hintz v2 claims the corresponding exterior-to-interior implication for a structured small-data class, but independent verification, extension to broader data, and the generic higher-regularity verdict remain unsettled. This replacement states system, symmetry, data, regularity, and missing interface.

  • An, Xinliang, and Hong Kiat Tan. “A Proof of Weak Cosmic Censorship Conjecture for the Spherically Symmetric Einstein–Maxwell–Charged Scalar Field System.” arXiv:2402.16250v1 (2024). arXiv v1.
  • An, Xinliang, and Shengrong Wu. “Naked Singularities beyond Spherical Symmetry: Singular Inner Cauchy Horizons for the Einstein–Scalar Field System.” arXiv:2607.07134v1 (2026). arXiv v1.
  • Choquet-Bruhat, Yvonne, and Robert Geroch. “Global Aspects of the Cauchy Problem in General Relativity.” Communications in Mathematical Physics 14 (1969): 329–335. DOI.
  • Christodoulou, Demetrios. “The Instability of Naked Singularities in the Gravitational Collapse of a Scalar Field.” Annals of Mathematics 149 (1999): 183–217. arXiv.
  • Dafermos, Mihalis, and Jonathan Luk. “The Interior of Dynamical Vacuum Black Holes I: The C0C^0-Stability of the Kerr Cauchy Horizon.” Annals of Mathematics 202 (2025): 309–630. DOI.
  • Davey, Alex, Óscar J. C. Dias, and David Sola Gil. “Strong Cosmic Censorship in Kerr–Newman–de Sitter.” Journal of High Energy Physics 2024, no. 7 (2024): 113. DOI.
  • Gurriaran, Sebastian. “Non-linear Instability of the Kerr Cauchy Horizon near i+i_+.” arXiv:2603.17911v2 (2026). arXiv v2.
  • Hintz, Peter. “Nonlinear Stability of Subextremal Kerr Black Holes.” arXiv:2606.28253v2 (2026). arXiv v2.
  • Isenberg, James. “On Strong Cosmic Censorship.” Surveys in Differential Geometry 20 (2015): 17–36. arXiv.
  • Luk, Jonathan, and Sung-Jin Oh. “Strong Cosmic Censorship in Spherical Symmetry for Two-Ended Asymptotically Flat Initial Data I: The Interior of the Black Hole Region.” Annals of Mathematics 190 (2019): 1–111. arXiv.
  • Luk, Jonathan, and Sung-Jin Oh. “Strong Cosmic Censorship in Spherical Symmetry for Two-Ended Asymptotically Flat Initial Data II: The Exterior of the Black Hole Region.” Annals of PDE 5 (2019): 6. arXiv.
  • Shlapentokh-Rothman, Yakov. “Naked Singularities for the Einstein Vacuum Equations: The Interior Solution.” arXiv:2204.09891v1 (2022). arXiv v1.
  • Van de Moortel, Maxime. “The Strong Cosmic Censorship Conjecture.” Comptes Rendus. Mécanique 353 (2025): 415–454. DOI. Open PDF.
  • Zheng, Weihao. “Nonlinear Stability of Continuously Self-Similar Naked Singularities for the Einstein–Scalar Field Equations I: Main Results.” arXiv:2605.16235v1 (2026). arXiv v1.