Gersten's acyclicity conjecture for regular local rings

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Let X=Spec⁡AX = \operatorname{Spec} A, where (A,mA,L)(A,\mathfrak{m}_A,L) is a regular local ring. For each n≥0n \geq 0, let Gn(X)\mathcal{G}_n(X) be the Gersten complex associated with the codimensional filtration, whose terms are built from the groups Kn−p(k(x))K_{n-p}(k(x)) at points of codimension pp. Gersten's Conjecture. The complex Gn(X)\mathcal{G}_n(X) resolves Kn(X)K_n(X), meaning

Hp(Gn(X))={Kn(X)p=00p>0.H^p(\mathcal{G}_n(X)) = \begin{cases} K_n(X) & p = 0 \\ 0 & p > 0. \end{cases}

This is the acyclicity conjecture for the Gersten complex of a regular local ring and is a central problem in algebraic KK-theory. The source does not specify a resolution status for the general statement.

References

Primary source

C. Skalit, “Regular Morphisms and Gersten's Conjecture”, arXiv:1710.00303 (2017).

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Solutions 2

RemarkAI-assistedClaimed by OpenAI. The manuscript claims a two-dimensional ramified regular local ring A of mixed characteristic (0,5) for which K_5(A) to K_5(Frac(A)) has nonzero kernel. This obstructs the natural first injectivity required by the page’s integral Gersten resolution and gives a claimed mixed-characteristic counterexample. It does not concern only Milnor K-theory, rational coefficients, or regular local rings containing a field.See full solutionHide full solution

Claimed by OpenAI. The manuscript claims a two-dimensional ramified regular local ring A of mixed characteristic (0,5) for which K_5(A) to K_5(Frac(A)) has nonzero kernel. This obstructs the natural first injectivity required by the page’s integral Gersten resolution and gives a claimed mixed-characteristic counterexample. It does not concern only Milnor K-theory, rational coefficients, or regular local rings containing a field.

GitHub repository: https://github.com/openai/math

Manuscript: https://github.com/openai/math/blob/adc7f1241b42e322a6451854ab7e4b4c146bf78a/preprints/An-Integral-Counterexample-to-Gerstens-Conjecture-September-25-2026/An-Integral-Counterexample-to-Gerstens-Conjecture-September-25-2026.pdf

  • OpenAI-209-01-An-integral-counterexample-to-Gersten-s-conjecture.pdf469,239 bytesOpen
RemarkAI-assistedClaimed by OpenAI. The manuscript claims a two-dimensional ramified regular local ring A of mixed characteristic (0,5) with nonzero kernel in the integral map K_3(A) to K_3(Frac(A)). This contradicts the natural first injectivity needed for the page’s Gersten resolution in degree three if the claim holds. The statement is a ramified mixed-characteristic example, not a claim about rational coefficients or only Milnor K-theory.See full solutionHide full solution

Claimed by OpenAI. The manuscript claims a two-dimensional ramified regular local ring A of mixed characteristic (0,5) with nonzero kernel in the integral map K_3(A) to K_3(Frac(A)). This contradicts the natural first injectivity needed for the page’s Gersten resolution in degree three if the claim holds. The statement is a ramified mixed-characteristic example, not a claim about rational coefficients or only Milnor K-theory.

GitHub repository: https://github.com/openai/math

Manuscript: https://github.com/openai/math/blob/adc7f1241b42e322a6451854ab7e4b4c146bf78a/preprints/An-Integral-Degree-Three-Gersten-Counterexample-September-26-2026/paper.pdf

  • OpenAI-209-02-An-integral-degree-three-Gersten-counterexample.pdf341,624 bytesOpen