Smooth 34-Dimensional IDP Polytopes with Nonunimodal h*-Polynomials
Manuscript 25 October 2026 · Online 25 October 2026
Abstract
Ferroni constructed smooth 40-dimensional lattice polytopes with the integer decomposition property whose h-star polynomials are not unimodal. This paper refines the parameters in his Cayley-box construction to obtain infinitely many pairwise lattice-inequivalent examples in dimension 34. For every integer t >= 1, the matrix [100000t*ones_17 | 1310000t*I_17] + J_(17x18) defines a smooth IDP polytope with h-star degree 17 and h15 > h16 < h17. Exact positivity of all coefficients of two gap polynomials in t-1 proves the inequalities uniformly. A standalone verifier independently reconstructs the polynomials by rational interpolation of direct interior counts and checks forward h-vectors. The associated Ehrhart rings are standard graded normal Cohen--Macaulay domains of dimension 35 and are not Gorenstein. This is a dimension refinement of Ferroni's prior counterexamples, not a first disproof of unimodality or a minimal-dimension claim. The general standard graded Gorenstein-domain unimodality question in OWR-15587-015 remains outside the result. AI-assisted, self-audited and unrefereed; no independent review, formal verification or absolute priority certification is claimed.
Record
- Affiliation
- Mercury Software GmbH
- Contact
- [email protected] · GitHub
- Result
- Complete counterexample family (dimension refinement)
- Categories
- math.CO · math.AC
- Manuscript
- 25 October 2026
- Online release
- 25 October 2026
- Version
- 1.0
- License
- Creative Commons Attribution 4.0 International
Files and verification
The PDF is the canonical reading copy. The source archive contains the LaTeX manuscript, bibliography, reproducibility material, and audit documents without build artefacts.
Citation
Alper Ferudun, “Smooth 34-Dimensional IDP Polytopes with Nonunimodal h*-Polynomials,” EulerSolve Research Papers, OWR-15587-015, 2026. https://doi.org/10.5281/zenodo.23638812.
BibTeX
@misc{ferudun2026smooth34,
author = {Ferudun, Alper},
title = {Smooth 34-Dimensional IDP Polytopes with Nonunimodal h*-Polynomials},
year = {2026},
howpublished = {EulerSolve Research Papers},
url = {https://eulersolve.org/papers/owr-15587-015/},
doi = {10.5281/zenodo.23638812},
note = {OWR-15587-015; unrefereed preprint}
}