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We show that the Ehrhart h-vector of an integer Gorenstein polytope with a regular unimodular triangulation satisfies McMullen's g-theorem; in particular, it is unimodal. This result generalizes a recent theorem of Athanasiadis (conjectured…

Commutative Algebra · Mathematics 2021-05-18 Winfried Bruns , Tim Roemer

An integral convex polytope ${\mathcal P}$ is said to be Gorenstein if its toric ring $K[{\mathcal P}]$ is normal and Gorenstein. In this paper, Gorenstein cut polytopes of graphs are characterized explicitly. First, we prove that…

Combinatorics · Mathematics 2019-01-11 Hidefumi Ohsugi

The matching polytope of a graph $G$ is the convex hull of the indicator vectors of the matchings on $G$. We characterize the graphs whose associated matching polytopes are Gorenstein, and then prove that all Gorenstein matching polytopes…

Combinatorics · Mathematics 2024-07-15 Benjamin Eisley , Koji Matsushita , Andrés R. Vindas-Meléndez

In this note we investigate the convex hull of those $n \times n$-permutation matrices that correspond to symmetries of a regular $n$-gon. We give the complete facet description. As an application, we show that this yields a Gorenstein…

Combinatorics · Mathematics 2012-12-19 Barbara Baumeister , Christian Haase , Benjamin Nill , Andreas Paffenholz

A cubical polytope is a polytope with all its facets being combinatorially equivalent to cubes. We deal with the connectivity of the graphs of cubical polytopes. We first establish that, for any $d\ge 3$, the graph of a cubical $d$-polytope…

Combinatorics · Mathematics 2019-07-16 Hoa T. Bui , Guillermo Pineda-Villavicencio , Julien Ugon

A Gorenstein polytope of index r is a lattice polytope whose r-th dilate is a reflexive polytope. These objects are of interest in combinatorial commutative algebra and enumerative combinatorics, and play a crucial role in Batyrev's and…

Combinatorics · Mathematics 2013-03-12 Benjamin Lorenz , Benjamin Nill

We investigate arithmetic, geometric and combinatorial properties of symmetric edge polytopes. We give a complete combinatorial description of their facets. By combining Gr\"obner basis techniques, half-open decompositions and methods for…

Combinatorics · Mathematics 2019-05-15 Akihiro Higashitani , Katharina Jochemko , Mateusz Michałek

Beck et. al. characterized the grid graphs whose perfect matching polytopes are Gorenstein and they also showed that for some parameters, perfect matching polytopes of torus graphs are Gorenstein. In this paper, we complement their result,…

Combinatorics · Mathematics 2008-03-11 Makoto Tagami

We study the Ehrhart $h^\ast$-polynomial of (the boundary of) a lattice polytope via regular unimodular triangulations and Gr\"obner degenerations of toric ideals. Our main result is a boundary analogue of the well-known Sturmfels…

Combinatorics · Mathematics 2026-04-28 Martina Juhnke , Steffen Schlie

Symmetric edge polytopes are a recent and well-studied family of centrally symmetric polytopes arising from graphs. In this paper, we introduce a generalization of this family to arbitrary simplicial complexes. We show how topological…

Combinatorics · Mathematics 2026-02-20 Torben Donzelmann , Thiago Holleben , Martina Juhnke

This dissertation investigates the geometric combinatorics of convex polytopes and connections to the behavior of the simplex method for linear programming. We focus our attention on transportation polytopes, which are sets of all tables of…

Combinatorics · Mathematics 2010-06-15 Edward D. Kim

A cubical polytope is a polytope with all its facets being combinatorially equivalent to cubes. The paper is concerned with the linkedness of the graphs of cubical polytopes. A graph with at least $2k$ vertices is \textit{$k$-linked} if,…

Combinatorics · Mathematics 2023-10-13 Hoa T. Bui , Guillermo Pineda-Villavicencio , Julien Ugon

Generalizing work of Athanasiadis for the Birkhoff polytope and Reiner and Welker for order polytopes, in 2007 Bruns and R\"omer proved that any Gorenstein lattice polytope with a regular unimodular triangulation admits a regular unimodular…

Combinatorics · Mathematics 2025-02-17 Benjamin Braun , Alvaro Cornejo

A long-standing open conjecture in combinatorics asserts that a Gorenstein lattice polytope with the integer decomposition property (IDP) has a unimodal (Ehrhart) $h^\ast$-polynomial. This conjecture can be viewed as a strengthening of a…

Combinatorics · Mathematics 2018-06-04 Benjamin Braun , Robert Davis , Liam Solus

Using a ribbon structure of the graph, we construct a dissection of the symmetric edge polytope of a graph into unimodular simplices. Our dissection is shellable, and one can interpret the elements of the resulting $h$-vector via graph…

Combinatorics · Mathematics 2022-01-26 Tamás Kálmán , Lilla Tóthmérész

It is a famous open question whether every integrally closed reflexive polytope has a unimodal Ehrhart delta-vector. We generalize this question to arbitrary integrally closed lattice polytopes and we prove unimodality for the delta-vector…

Combinatorics · Mathematics 2011-10-18 Jan Schepers , Leen Van Langenhoven

On the basis of recent results on hamiltonicity and hamiltonian connectedness in the square of a 2-block, we determine the most general block-cutvertex structure a graph $G$ may have in order to guarantee that $G^2$ is hamiltonian,…

Combinatorics · Mathematics 2023-09-28 J. Ekstein , H. Fleischner

Given a graph G, we construct a convex polytope whose face poset is based on marked subgraphs of G. Dubbed the graph multiplihedron, we provide a realization using integer coordinates. Not only does this yield a natural generalization of…

Quantum Algebra · Mathematics 2015-06-16 Satyan L. Devadoss , Stefan Forcey

We study the relationship between the vertices of an up-monotone polyhedron $R$ and those of the polytope $P$ obtained by truncating $R$ with the unit hypercube. When $R$ has binary vertices, we characterize the vertices of $P$ in terms of…

Combinatorics · Mathematics 2018-01-08 Néstor E. Aguilera , Ricardo D. Katz , Paola B. Tolomei

The characterization of lattice polytopes based upon information about their Ehrhart $h^*$-polynomials is a difficult open problem. In this paper, we finish the classification of lattice polytopes whose $h^*$-polynomials satisfy two…

Combinatorics · Mathematics 2015-03-20 Akihiro Higashitani , Benjamin Nill , Akiyoshi Tsuchiya
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