Preserving Hodge vectors of lattice polytopes
- 1Otto-von-Guericke-Universität Magdeburg, Faculty of Mathematics, Universitätsplatz 2, 39106 Magdeburg (Germany)
Abstract
In Ehrhart theory, the local h * -polynomial is a fundamental invariant of a lattice polytope. Its coefficient vector, the local h * -vector, is the coefficient vector of the top degree part of the Hodge-Deligne polynomial of the primitive cohomology with compact support of the associated generic hypersurface in the algebraic torus. In the literature on hypergeometric motives, the Hodge vector of a lattice polytope is its local h * -vector with leading and trailing zeroes removed. Of recent special interest are thin polytopes whose Hodge vectors vanish.
Given lattice polytopes P 1 , ⋯ , P k contained in a k -dimensional subspace U ⊆ ℝ d and a d -dimensional lattice polytope P ⊂ ℝ d , we compute the Hodge vector of the Cayley polytope P 1 * ⋯ * P k * P , and show that it equals the mixed volume of P 1 , ... , P k times the Hodge vector of the projection of P along U . This allows finding infinitely many high-dimensional lattice polytopes with the same Hodge vector that are not free joins. The proof relies on a closed formula for the Hodge-Deligne polynomial of generic complete intersections in the torus in terms of the bivariate/mixed h * -polynomial. A special case of our construction is what we call Lawrence twists: extending the Gale transform by centrally-symmetric pairs of vectors. As applications, we can produce many new thin polytopes answering a question by Borger, Kretschmer and the second author, and we provide an alternative explanation of the thinness of B k -polytopes answering a question of Selyanin.
Related
- Palindromic real-rooted polynomials and h-vectors of polytopes
- Hilbert functions over the exterior algebra and f-vectors in higher rank I: Amata-Crupi monomial modules, Kozlov polytopes, and r-vectors of simplicial complexes
- Quasi-polynomial valuations of lattice polytopes
- Weighted lattice point enumeration in lecture hall order polytopes
- Ehrhart Properties under Operations on Lattice Polytopes
BibTeX
@article{kurylenko2026preserving,
title = {{Preserving Hodge vectors of lattice polytopes}},
author = {Vadym Kurylenko and Benjamin Nill},
journal = {Algebraic Combinatorics},
year = {2026},
month = oct,
doi = {10.5802/alco.515},
url = {https://alco.centre-mersenne.org/articles/10.5802/alco.515/},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Preserving Hodge vectors of lattice polytopes
AU - Vadym Kurylenko
AU - Benjamin Nill
PY - 2026
DA - 2026/10/27
JO - Algebraic Combinatorics
DO - 10.5802/alco.515
UR - https://alco.centre-mersenne.org/articles/10.5802/alco.515/
AB - In Ehrhart theory, the local h * -polynomial is a fundamental invariant of a lattice polytope. Its coefficient vector, the local h * -vector, is the coefficient vector of the top degree part of the Hodge-Deligne polynomial of the primitive cohomology with compact support of the associated generic hypersurface in the algebraic torus. In the literature on hypergeometric motives, the Hodge vector of a lattice polytope is its local h * -vector with leading and trailing zeroes removed. Of recent special interest are thin polytopes whose Hodge vectors vanish. Given lattice polytopes P 1 , ⋯ , P k contained in a k -dimensional subspace U ⊆ ℝ d and a d -dimensional lattice polytope P ⊂ ℝ d , we compute the Hodge vector of the Cayley polytope P 1 * ⋯ * P k * P , and show that it equals the mixed volume of P 1 , ... , P k times the Hodge vector of the projection of P along U . This allows finding infinitely many high-dimensional lattice polytopes with the same Hodge vector that are not free joins. The proof relies on a closed formula for the Hodge-Deligne polynomial of generic complete intersections in the torus in terms of the bivariate/mixed h * -polynomial. A special case of our construction is what we call Lawrence twists: extending the Gale transform by centrally-symmetric pairs of vectors. As applications, we can produce many new thin polytopes answering a question by Borger, Kretschmer and the second author, and we provide an alternative explanation of the thinness of B k -polytopes answering a question of Selyanin.
SN - 2589-5486
ER -