Integral K5 injectivity for regular local domains
Status OpenLLM status Open unverified
Top Open Problems unknownunknown Not reported cataloguedOpenOpenStatement
Definitions and mathematical statement
Statement recorded in the supplied source.
For every Noetherian regular local domain A with fraction field F, is the canonical map on integral algebraic K-groups $K_{5}(A)\to K_{5}(F)$ injective, including ramified mixed characteristic?Short English statement
For every Noetherian regular local domain A with fraction field F, is the canonical map on integral algebraic K-groups $K_{5}(A)\to K_{5}(F)$ injective, including ramified mixed characteristic?Sources
- S1 OpenAI, manuscript citation page. Source of the formulation motivating this local problem. https://github.com/openai/math/blob/adc7f1241b42e322a6451854ab7e4b4c146bf78a/preprints/An-Integral-Counterexample-to-Gerstens-Conjecture-September-25-2026/README.md.
Statement licence: CC-BY-4.0 · Source file
Contributions 1
OpenAI claim summary for Math-2518
The ring has Krull dimension two and is regular, local, and ramified in characteristic pair $(0,5)$. A nonzero integral class in degree five becomes zero in the fraction field, which already contradicts the unrestricted first Gersten injection. This is presented as a claimed negative answer.
Integral K5 injectivity for regular local domains
OpenAI's claim
OpenAI presents a counterexample in the selected manuscript. A ramified regular local ring of dimension two in characteristic pair $(0,5)$ is claimed to have a nonzero integral $K_5$ class that dies over its fraction field.Mathematical statement of the claimed result
Result 1.
Let $V$ be the integer ring of the unramified degree-eight extension of $\mathbb Q_5$. For \[ A=(V[x,y]/(5+x^4+y^4))_{(5,x,y)}, \] the source claims $A$ is a two-dimensional Noetherian regular local domain and \[ \ker(K_5(A)\to K_5(\operatorname{Frac}A))\ne0. \] The failure is for integral Quillen $K_5$, without tensoring with the rationals.Outline of the argument
Cyclotomic Bott classes on a quartic model are lifted integrally using a $K_4$ vanishing statement. Supported pushforward guarantees generic disappearance, while character averaging and Picard specialization on an elliptic quotient detect the surviving class modulo five.Formal verification
Family 209 has no Lean scope page in this release. Its selected result is not presented as formalized. This site has not executed the Lean code. The scope descriptions do not certify the remaining manuscript arguments.Status caveat
OpenAI attributes these manuscripts to work by an internal model. Its release cautions that arguments without formalization can contain mistakes. This catalogue has not independently checked the proofs; the labels report the mathematical claims attributed to OpenAI.Sources
- OpenAI, An integral counterexample to Gersten's conjecture, 2026-09-25; citation key
OAI:An-Integral-Counterexample-to-Gerstens-Conjecture-September-25-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main. - OpenAI catalogue entry.