{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"0b0503dee8170293cdca7b61e051f7818d79d7d1d404010eb2fc59889bfbef67","created":"2026-10-03T07:18:04Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"5ba2efb46c6f4f632911169dd088cddad82b9bae39389048da9cf2d9a8efec1b","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"proof","assisted_by":[],"external_id":"grav.singularities-censorship.black-string-pinchoff","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"In five spacetime dimensions a long thin black hole shaped like a string breaks into a chain of smaller black holes, much as a stream of water breaks into drops. Simulations show the pinch-off exposes a singularity to distant observers without fine tuning, but there is no proof.","posed_since":"2010","precise":"For the vacuum Einstein equations on asymptotically $R^{3,1} x S^1$ with data near a uniform black string above the Gregory-Laflamme threshold (the length above which the string is unstable), numerical evolution shows a self-similar cascade of thinning necks reaching zero radius in finite asymptotic time (Lehner and Pretorius 2010); thin black rings in asymptotically flat 5D behave similarly (Figueras, Kunesch, Tunyasuvunakool 2016). Prove that an open set of such data yields a maximal development with incomplete future null infinity, a generic violation of weak cosmic censorship in $D = 5$, or prove that the cascade halts.","problem_ref":null,"references":"","settled_by":"A rigorous analysis of the nonlinear Gregory-Laflamme evolution establishing or excluding finite-time pinch-off for an open set of data.","status_note":"Numerical evidence (2010, 2016) supports finite-time pinch-off in pure gravity; simulations with a positive Gauss-Bonnet correction find curvature growth bounded within effective-field-theory limits (Figueras, Kovacs, Yao, arXiv:2606.05319, 2026); no rigorous proof as of 2026.","title":"Prove generic naked singularity formation from five-dimensional black string instability","topic_ref":"8b19c125ce8ffc5355cad7a14e54dbe37cd8a883144325702998d078b535110b"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"8cd5253431d0e838a80885d282a0c27b9a1d3fdd9eedf5ad477d50ff6ef898a6","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"1b18915460be8d05dca200c41c1e086928743a57d339385f46139af2aa7b59bf","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"mX7wtxkZ3ssmNFGMGm1dLGZxf-RUuMkQOtnot-5vScvBFe_R2pe2VRA5MFxvAI1pwarXQcyaPTPD-E32mI-8DA"},"schema":"pubphys.envelope/1"},"record_hash":"8cd5253431d0e838a80885d282a0c27b9a1d3fdd9eedf5ad477d50ff6ef898a6","leaf_index":1503}