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Related papers: A bijective proof for a theorem of Ehrhart

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Hibi showed that the polynomial in the numerator of the Ehrhart series of a reflexive polytope is palindromic. We proved that those in the numerator of the Ehrhart series of every graph polytope (defined later) of the bipartite graph is…

Combinatorics · Mathematics 2015-07-24 Daeseok Lee , Hyeong-Kwan Ju

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 give novel and explicit formulas for the Ehrhart quasi-polynomials of rational simple polytopes, in terms of Barnes polynomials and discrete moments of half-open parallelepipeds. These formulas also hold for all positive dilations of a…

Combinatorics · Mathematics 2026-02-02 Sinai Robins

We study the Ehrhart theory of quadratic irrational polytopes that undergo vector dilations. That is, for a given polytope with vertices in $\mathbb{Q}(\sqrt{D})$, and a different dilation factor for each facet, we show that the leading…

Number Theory · Mathematics 2018-10-03 Yashaswika Gaur , Tian An Wong

The Ehrhart polynomial and Ehrhart series count lattice points in integer dilations of a lattice polytope. We introduce and study a $q$-deformation of the Ehrhart series, based on the notions of harmonic spaces and Macaulay's inverse…

Combinatorics · Mathematics 2024-09-25 Victor Reiner , Brendon Rhoades

We present a polynomial time algorithm to compute any fixed number of the highest coefficients of the Ehrhart quasi-polynomial of a rational simplex. Previously such algorithms were known for integer simplices and for rational polytopes of…

Combinatorics · Mathematics 2007-05-23 Alexander Barvinok

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

It was observed by Bump et al. that Ehrhart polynomials in a special family exhibit properties similar to the Riemann {\zeta} function. The construction was generalized by Matsui et al. to a larger family of reflexive polytopes coming from…

Combinatorics · Mathematics 2018-04-20 Akihiro Higashitani , Mario Kummer , Mateusz Michałek

The Ehrhart function $L_P(t)$ of a polytope $P$ is usually defined only for integer dilation arguments $t$. By allowing arbitrary real numbers as arguments we may also detect integer points entering (or leaving) the polytope in fractional…

Combinatorics · Mathematics 2017-12-13 Tiago Royer

In this paper we investigate the Ehrhart Theory of the independence matroid polytope of uniform matroids. It is proved that these polytopes have an Ehrhart polynomial with positive coefficients. To do that, we prove that indeed all…

Combinatorics · Mathematics 2021-05-24 Luis Ferroni

We examine two different ways of encoding a counting function, as a rational generating function and explicitly as a function (defined piecewise using the greatest integer function). We prove that, if the degree and number of input…

Combinatorics · Mathematics 2015-05-08 Sven Verdoolaege , Kevin Woods

Motivated by representation theory and geometry, we introduce and develop an equivariant generalization of Ehrhart theory, the study of lattice points in dilations of lattice polytopes. We prove representation-theoretic analogues of…

Combinatorics · Mathematics 2014-12-05 Alan Stapledon

This article concerns the computational problem of counting the lattice points inside convex polytopes, when each point must be counted with a weight associated to it. We describe an efficient algorithm for computing the highest degree…

Combinatorics · Mathematics 2010-11-09 Velleda Baldoni , Nicole Berline , Jesús A. De Loera , Matthias Köppe , Michèle Vergne

Recently, Chapoton found a $q$-analog of Ehrhart polynomials, which are polynomials in $x$ whose coefficients are rational functions in $q$. Chapoton conjectured the shape of the Newton polygon of the numerator of the $q$-Ehrhart polynomial…

Combinatorics · Mathematics 2018-06-05 Jang Soo Kim , U-Keun Song

We introduce a powerful connection between Ehrhart theory and additive number theory, and use it to produce infinitely many new classes of inequalities between the coefficients of the $h^*$-polynomial of a lattice polytope. This greatly…

Combinatorics · Mathematics 2021-10-05 Alan Stapledon

We give new proofs of three theorems of Stanley on generating functions for the integer points in rational cones. The first, Stanley's reciprocity theorem, relates the rational generating functions for the integer points in a cone K and for…

Combinatorics · Mathematics 2007-05-25 Matthias Beck , Frank Sottile

The Ehrhart quasipolynomial of a rational polytope $P$ encodes the number of integer lattice points in dilates of $P$, and the $h^*$-polynomial of $P$ is the numerator of the accompanying generating function. We provide two decomposition…

Combinatorics · Mathematics 2024-09-24 Matthias Beck , Benjamin Braun , Andrés R. Vindas-Meléndez

Given a rational polytope $P \subset \mathbb R^d$, the numerical function counting lattice points in the integral dilations of $P$ is known to become a quasi-polynomial, called the Ehrhart quasi-polynomial $\mathrm{ehr}_P$ of $P$. In this…

Combinatorics · Mathematics 2024-11-01 Akihiro Higashitani , Satoshi Murai , Masahiko Yoshinaga

Motivated by questions from Ehrhart theory, we present new results on discrete equidecomposability. Two rational polygons $P$ and $Q$ are said to be discretely equidecomposable if there exists a piecewise affine-unimodular bijection…

Combinatorics · Mathematics 2014-12-02 Paxton Turner , Yuhuai Wu

A positroid is a matroid realized by a matrix such that all maximal minors are non-negative. Positroid polytopes are matroid polytopes of positroids. In particular, they are lattice polytopes. The Ehrhart polynomial of a lattice polytope…

Combinatorics · Mathematics 2025-01-20 Yuhan Jiang