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Let $P$ be a polytope with rational vertices. A classical theorem of Ehrhart states that the number of lattice points in the dilations $P(n) = nP$ is a quasi-polynomial in $n$. We generalize this theorem by allowing the vertices of P(n) to…

Combinatorics · Mathematics 2011-09-28 Sheng Chen , Nan Li , Steven V Sam

It is possible to write the indicator function of any matroid polytope as an integer combination of indicator functions of Schubert matroid polytopes. In this way, every matroid on $n$ elements of rank $r$ can be thought of as a lattice…

Combinatorics · Mathematics 2025-08-14 Luis Ferroni , Alex Fink

To any poset or quasi-poset is attached a lattice polytope, whose Ehrhart polynomial we study from a Hopf-algebraic point of view. We use for this two interacting bialgebras on quasi-posets. The Ehrhart polynomial defines a Hopf algebra…

Rings and Algebras · Mathematics 2016-11-15 Loïc Foissy

It is already known that order polytopes and chain polytopes are always 2-level polytopes. In general, this is not true for marked order and marked chain polytopes. We study the geometry of marked order polytopes, marked chain polytopes,…

Combinatorics · Mathematics 2025-03-26 Jan Stricker

Reflexive lattice polytopes play a key role in combinatorics, algebraic geometry, physics, and other areas. One important class of lattice polytopes are lattice simplices defining weighted projective spaces. We investigate the question of…

Combinatorics · Mathematics 2022-11-23 Benjamin Braun , Robert Davis , Derek Hanely , Morgan Lane , Liam Solus

We address the problem of defining Schubert classes independently of a reduced word in equivariant elliptic cohomology, based on the Kazhdan-Lusztig basis of a corresponding Hecke algebra. We study some basic properties of these classes,…

Algebraic Geometry · Mathematics 2016-02-09 Cristian Lenart , Kirill Zainoulline

In this paper, we investigate two properties concerning the unimodality of the $\delta$-vectors of lattice polytopes, which are log-concavity and alternatingly increasingness. For lattice polytopes $\mathcal{P}$ of dimension $d$, we prove…

Combinatorics · Mathematics 2015-04-17 Akihiro Higashitani

If $P$ is a lattice polytope (i.e., $P$ is the convex hull of finitely many integer points in $\mathbb{R}^d$) of dimension $d$, Ehrhart's famous theorem (1962) asserts that the integer-point counting function $|nP \cap \mathbb{Z}^d|$ is a…

Combinatorics · Mathematics 2024-09-24 Esme Bajo , Matthias Beck

Matroids give rise to several natural constructions of polytopes. Inspired by this, we examine polytopes that arise from the signed circuits of an oriented matroid. We give the dimensions of these polytopes arising from graphical oriented…

Combinatorics · Mathematics 2025-01-03 Laura Escobar , Jodi McWhirter

There is a well-established dictionary between zonotopes, hyperplane arrangements, and their (oriented) matroids. Arguably one of the most famous examples is the class of graphical zonotopes, also called acyclotopes, which encode…

Combinatorics · Mathematics 2024-09-24 Eleonore Bach , Matthias Beck , Sophie Rehberg

Ehrhart theory measures a polytope P discretely by counting the lattice points inside its dilates P, 2P, 3P, .... We compute the Ehrhart quasipolynomials of the standard Coxeter permutahedra for the classical Coxeter groups, expressing them…

Combinatorics · Mathematics 2021-12-21 Federico Ardila , Matthias Beck , Jodi McWhirter

We establish a connection between the orbifold cohomology of hypertoric varieties and the Ehrhart theory of Lawrence polytopes. More specifically, we show that the dimensions of the orbifold cohomology groups of a hypertoric variety are…

Combinatorics · Mathematics 2009-09-24 Alan Stapledon

We present an algorithm for growing the denominator $r$ polygons containing a fixed number of lattice points and enumerate such polygons containing few lattice points for small $r$. We describe the Ehrhart quasi-polynomial of a rational…

Combinatorics · Mathematics 2024-12-02 Girtrude Hamm , Johannes Hofscheier , Alexander Kasprzyk

We describe a genetic algorithm to find candidates for $h^*$-vectors satisfying given properties in the space of integers vectors of finite length. We use an implementation of such algorithm to find a 52-dimensional lattice polytope having…

Combinatorics · Mathematics 2024-10-25 Gabriele Balletti

Positive geometries encode the physics of scattering amplitudes in flat space-time and the wavefunction of the universe in cosmology for a large class of models. Their unique canonical forms, providing such quantum mechanical observables,…

High Energy Physics - Theory · Physics 2020-08-26 Paolo Benincasa , Matteo Parisi

Stanley introduced a lattice polytope $\mathcal{C}_P$ arising from a finite poset $P$, which is called the chain polytope of $P$. The geometric structure of $\mathcal{C}_P$ has good relations with the combinatorial structure of $P$. In…

Combinatorics · Mathematics 2020-09-07 Hidefumi Ohsugi , Akiyoshi Tsuchiya

We express the generating function for lattice points in a rational polyhedral cone with a simplicial subdivision in terms of multivariate analogues of the h-polynomials of the subdivision and "local contributions" of the links of its…

Combinatorics · Mathematics 2008-12-07 Sam Payne

We study the class of Lorentzian polynomials. The class contains homogeneous stable polynomials as well as volume polynomials of convex bodies and projective varieties. We prove that the Hessian of a nonzero Lorentzian polynomial has…

Combinatorics · Mathematics 2024-07-18 Petter Brändén , June Huh

We introduce a new matroid (graph) invariant, the arboricity polynomial. Given a matroid, the arboricity polynomial enumerates the number of covers of the ground set by disjoint independent sets. We establish the polynomiality of the…

Combinatorics · Mathematics 2025-05-09 Felix Breuer , Caroline J Klivans

Let $P_{\lambda\Sigma_n}$ be the Ehrhart polynomial associated to an intergal multiple $\lambda$ of the standard symplex $\Sigma_n \subset \mathbb{R}^n$. In this paper we prove that if $(M, L)$ is an $n$-dimensional polarized toric manifold…

Differential Geometry · Mathematics 2022-06-29 Andrea Loi , Fabio Zuddas