Zariski–Lipman conjecture
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Definitions and mathematical statement
Shared notation.
$\mathbb N$, $\mathbb Z$, $\mathbb Q$, $\mathbb R$, and $\mathbb C$ denote the natural numbers, integers, rationals, reals, and complex numbers, respectively. All additional parameters and hypotheses are specified in the question.Statement recorded in the supplied source.
Let $V$ be a complex algebraic variety with coordinate ring $R$. If the module of derivations of $R$ is free over $R$, must $V$ be smooth?Formulation references: [S1], [S2].
Short English statement
Let $V$ be a complex algebraic variety with coordinate ring $R$. If the module of derivations of $R$ is free over $R$, must $V$ be smooth?Sources
- S1 ULAM.AI and the UnsolvedMath Contributors, UnsolvedMath: A Curated Collection of Open Mathematics Problems, record 1600031 (AMR-015-0031). Catalogue attribution under CC BY 4.0. https://huggingface.co/datasets/ulamai/UnsolvedMath.
- S2 Original problem formulation and mathematical context. https://en.wikipedia.org/w/index.php?title=List_of_unsolved_problems_in_mathematics&oldid=1366636767.
Statement licence: CC-BY-4.0 · Source file
Contributions 1
OpenAI claim summary for Math-2211
Manuscript 1 (family 048, 2026-09-23): The normal integral affine complex surface has Der_C(A) free of rank two but a nonregular maximal localization. Thus its tangent/derivation module is free while the variety is singular, directly refuting the stated implication.
Zariski–Lipman conjecture
OpenAI's claim
A singular normal affine complex surface is claimed to have a globally free rank-two tangent sheaf, contradicting the characteristic-zero Lipman--Zariski assertion. The cited manuscript argues for that result; its relation to this problem is specified below.Mathematical statement of the claimed result
Mathematical claim 1.
OpenAI claims a normal integral $\mathbb C$-algebra $A$, required to be finitely generated and two-dimensional in the Krull sense, together with a maximal ideal $\mathfrak m$ with \[ \operatorname{Der}_{\mathbb C}(A)\simeq A^{\oplus2},\qquad A_{\mathfrak m}\text{ not regular}. \] Thus the associated normal affine complex surface is singular despite a globally free rank-two tangent module. Freeness is as an $A$-module and regularity is the local-ring condition.Outline of the argument
Manuscript 1 (family 048, 2026-09-23): The analytic seed is a negative-curve neighborhood whose gluing is modified without changing its normal bundle. Two vector fields are built with a nonvanishing determinant off the curve by simultaneous point corrections and global residue constraints; algebraization preserves the completed singularity and allows tangent freeness to descend.Formal verification
Family 048 has no Lean scope page in this snapshot; no formalization of these manuscript results is listed.This site has not executed the Lean files or checked their dependencies. These descriptions report the scope of the linked declarations, rather than a new verification of the proofs.
Status caveat
OpenAI attributes these results to an internal model. Its release notice cautions that results lacking full formalization can contain mistakes. This site has not independently assessed the proofs; a solved label records the scope of the reported claim.Sources
- OpenAI, A singular normal affine surface with free tangent sheaf, 2026-09-23; citation key
OAI:A-singular-normal-affine-surface-with-free-tangent-sheaf-September-23-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main. - OpenAI catalogue entry.