Math-2560 · mathematics · Algebraic geometry

Math-2560

A geometric criterion for Kuga–Satake algebraicity

Status OpenLLM status Open unverified

Top Open Problems unknownunknown Not reported cataloguedOpenOpen

Statement

Definitions and mathematical statement

Statement recorded in the supplied source.
Let (S,h) be a primitively amply polarized projective complex K3 surface. Put $V=h\perp $ in $H^{2}(S,Q)$, with its primitive quadratic Hodge structure, and assume $Hg(V)=SO(V,q)$, so $T(S)=V$. Are the following three conditions equivalent? First, some rational codimension-two correspondence from S to a complex abelian variety acts nontrivially on V. Second, there is a smooth connected projective surface Y and a dominant generically finite morphism $f:Y\to S$ such that tracing the wedge products of holomorphic one-forms on Y to $H^{0}(S,\Omega ^{2}_S)$ gives a nonzero map. Third, for every specified standard full Kuga–Satake Clifford, polarization and realization datum, a rational codimension-two cycle induces the prescribed Kuga–Satake map on $T(S)=V$.

Short English statement

Let (S,h) be a primitively amply polarized projective complex K3 surface. Put $V=h\perp $ in $H^{2}(S,Q)$, with its primitive quadratic Hodge structure, and assume $Hg(V)=SO(V,q)$, so $T(S)=V$. Are the following three conditions equivalent? First, some rational codimension-two correspondence from S to a complex abelian variety acts nontrivially on V. Second, there is a smooth connected projective surface Y and a dominant generically finite morphism $f:Y\to S$ such that tracing the wedge products of holomorphic one-forms on Y to $H^{0}(S,\Omega ^{2}_S)$ gives a nonzero map. Third, for every specified standard full Kuga–Satake Clifford, polarization and realization datum, a rational codimension-two cycle induces the prescribed Kuga–Satake map on $T(S)=V$.

Sources

Statement licence: CC-BY-4.0 · Source file

Contributions 1

Math-2560-A1 · Literature report · LLM-generated · unknown ·

OpenAI claim summary for Math-2560

Manuscript 1 (family 032, 2026-09-10): The problem selects the mathematical statement summarized here, including its stated hypotheses and parameter range. The cited theorem gives a claimed proof of that assertion in full.

A geometric criterion for Kuga–Satake algebraicity

OpenAI's claim

A nonzero algebraic map from generic primitive K3 cohomology to an abelian target is claimed to recover the exact Kuga--Satake correspondence; existence of that starting map remains an assumption. The cited manuscript argues for that result; its relation to this problem is specified below.

Mathematical statement of the claimed result

Mathematical claim 1.
Let $(S,h)$ be a primitively amply polarized projective complex K3 surface, put $V=h^\perp\subset H^2(S,\mathbb Q)$ with cup-product form $q$, and assume $\operatorname{Hg}(V)=\operatorname{SO}(V,q)$. This hypothesis implies $T(S)=\operatorname{NS}(S)_{\mathbb Q}^{\perp}=V$. For any stipulated rational quadratic polarization and full standard even-Clifford Kuga--Satake construction, including parity, weight-one polarization and isogenous realization, write $A_S$ for its abelian variety and $\kappa_S:V\to H^2(A_S^2,\mathbb Q)$ for the prescribed map. OpenAI asserts equivalence of these three existence statements: (i) some abelian variety $B$ admits a rational codimension-two cycle on $S\times B$ inducing a nonzero map from $V$ to $H^2(B,\mathbb Q)$; (ii) a smooth connected projective surface $Y$ admits a dominant generically finite map $f:Y\to S$ with \[ f_*\operatorname{im}\left(\bigwedge^2 H^0(Y,\Omega_Y^1)\longrightarrow H^0(Y,\Omega_Y^2)\right)\ne0; \] (iii) some $\Gamma\in\operatorname{CH}^2(S\times A_S^2)_{\mathbb Q}$ satisfies $\Gamma_*|_V=\kappa_S$. Thus algebraicity is conditional on either equivalent geometric input; this theorem does not assert that every K3 surface has that input.

Outline of the argument

Manuscript 1 (family 032, 2026-09-10): Acting independently on each weight-one factor reconstructs the Clifford multiplicities, and rational descent treats nonsplit algebras. Hilbert parameter spaces carry the specified flat cycle class to special periods, while signed square-root comparisons keep the polarization normalization fixed.

Formal verification

Family 032 has no Lean scope page in this snapshot; no formalization of these manuscript results is listed.

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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.

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