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Betke–Henk–Wills lattice-point conjecture

Let K⊂RnK\subset\mathbb{R}^n be an origin-symmetric convex body and let Λ⊂Rn\Lambda\subset\mathbb{R}^n be a lattice. For 1≤i≤n1\le i\le n, define the ii-th successive minimum by λi(K,Λ)=inf⁡{λ>0:dim⁡span⁡(λK∩Λ)≥i}\lambda_i(K,\Lambda)=\inf\{\lambda>0:\dim\operatorname{span}(\lambda K\cap\Lambda)\ge i\}. Then

#(K∩Λ)≤∏i=1n(2⌊1λi(K,Λ)⌋+1).\#(K\cap\Lambda)\le\prod_{i=1}^n\left(2\left\lfloor\frac{1}{\lambda_i(K,\Lambda)}\right\rfloor+1\right).

A nonsymmetric extension, involving the successive minima of a general convex body, is also conjectured and remains open in full generality.

References

Progress summary

Refreshed
Open · progress reported

A new preprint proves the key sufficient condition in rank two, but the full conjecture remains open in higher rank.

Betke, Henk, and Wills conjectured that the number of lattice points in a symmetric convex body is bounded by a product determined by its successive minima. The conjecture also has a nonsymmetric extension; neither version is known in full generality.

Known results

  • The symmetric conjecture holds in dimension 22 (Betke–Henk–Wills).
  • The nonsymmetric extension holds through dimension 33 (Malikiosis, 2012).
  • Tointon’s October 1, 2024 paper gives improved bounds and verifies the conjecture asymptotically in a regime where the relevant successive minimum tends to 00.
  • Wang proves the bound for axis-aligned orthogonal parallelotopes and gives stability results for related shapes (2026).

October 2026 rank-two development

Fei Xue’s preprint establishes a sufficient discrete-monotonicity condition for the Betke–Henk–Wills bound and its nonsymmetric extension in arbitrary ambient dimension when the rank is at most 22. This is substantial partial progress, but it does not settle higher-rank cases; the preprint’s claim remains unverified here.

Current status (as of October 2026): The symmetric conjecture is settled in dimension 22 and the nonsymmetric extension through dimension 33, while Xue’s rank-two sufficient condition is claimed in arbitrary dimension; the full conjecture and higher-rank cases remain open.

Sources

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