English
Related papers

Related papers: Partial permutohedra

200 papers

We derive a formula for the number of lattice points in type B generalized permutohedra, providing a concise alternative to the formula obtained recently by Eur, Fink, Larson, and Spink as a result from a study of delta-matroids. Our…

Combinatorics · Mathematics 2025-12-02 Warut Thawinrak

This paper is to study the Ehrhart function $L(P,t)$ of a rational $n$-polytope $P$, defined as the number of lattice points of dilated polytopes $tP$ with real numbers $t\geq 0$. It turns out that $L(P,t)$ is a quasi-polynomial of real…

Combinatorics · Mathematics 2026-05-12 Ying Cao , Beifang Chen

Let n >= 2 be an integer and consider the set T_n of n by n permutation matrices pi for which pi_{ij}=0 for j>=i+2. In this paper we study the convex hull of T_n, which we denote by P_n. P_n is a polytope of dimension binom{n}{2}. Our main…

Combinatorics · Mathematics 2007-05-23 Clara S. Chan , David P. Robbins , David S. Yuen

We give a new definition of lattice-face polytopes by removing an unnecessary restriction in the paper "Ehrhart polynomials of lattice-face polytopes", and show that with the new definition, the Ehrhart polynomial of a lattice-face polytope…

Combinatorics · Mathematics 2008-10-28 Fu Liu

We study the harmonic polytope, which arose in Ardila, Denham, and Huh's work on the Lagrangian geometry of matroids. We describe its combinatorial structure, showing that it is a $(2n-2)$-dimensional polytope with…

Combinatorics · Mathematics 2021-07-05 Federico Ardila , Laura Escobar

There is a simple formula for the Ehrhart polynomial of a cyclic polytope. The purpose of this paper is to show that the same formula holds for a more general class of polytopes, lattice-face polytopes. We develop a way of decomposing any…

Combinatorics · Mathematics 2007-05-23 Fu Liu

We show that given a poset P and and a subposet Q, the integer points obtained by restricting linear extensions of P to Q can be explained via integer lattice points of a generalized permutohedron.

Combinatorics · Mathematics 2013-09-10 Dorian Croitoru , SuHo Oh , Alexander Postnikov

For a convex lattice polytope $P\subset \mathbb R^d$ of dimension $d$ with vertices in $\mathbb Z^d$, denote by $L(P)$ its discrete volume which is defined as the number of integer points inside $P$. The classical result due to Ehrhart says…

Metric Geometry · Mathematics 2021-07-15 Mariia Dospolova

The permutohedron $P_n$ of order $n$ is a polytope embedded in $\mathbb{R}^n$ whose vertex coordinates are permutations of the first $n$ natural numbers. It is obvious that $P_n$ lies on the hyperplane $H_n$ consisting of points whose…

Combinatorics · Mathematics 2026-04-10 Bochao Kong , Ji Zeng

The face poset of the permutohedron realizes the combinatorics of linearly ordered partitions of the set $[n]=\{1,...,n\}$. Similarly, the cyclopermutohedron is a virtual polytope that realizes the combinatorics of cyclically ordered…

Metric Geometry · Mathematics 2016-02-02 Ilia Nekrasov , Gaiane Panina , Alena Zhukova

For lattice polytopes $P_1,\ldots, P_k \subseteq \mathbb{R}^d$, Bihan (2014) introduced the discrete mixed volume $\mathrm{DMV}(P_1,\dots,P_k)$ in analogy to the classical mixed volume. In this note we initiate the study of the associated…

Combinatorics · Mathematics 2017-01-10 Christian Haase , Martina Juhnke-Kubitzke , Raman Sanyal , Thorsten Theobald

Given a real closed polytope $P$, we first describe the Fourier transform of its indicator function by using iterations of Stokes' theorem. We then use the ensuing Fourier transform formulations, together with the Poisson summation formula,…

Combinatorics · Mathematics 2018-08-02 Ricardo Diaz , Quang-Nhat Le , Sinai Robins

We study the problem of counting lattice points of a polytope that are weighted by an Ehrhart quasi-polynomial of a family of parametric polytopes. As applications one can compute integrals and maximum values of such quasi-polynomials, as…

Combinatorics · Mathematics 2024-02-20 Jesús A. De Loera , Laura Escobar , Nathan Kaplan , Chengyang Wang

A lattice polytope translated by a rational vector is called an almost integral polytope. In this paper we investigate Ehrhart quasi-polynomials of almost integral polytopes. We study the relationship between the shape of the polytopes and…

Combinatorics · Mathematics 2023-08-31 Christopher de Vries , Masahiko Yoshinaga

Generalizing a conjecture by De Loera et al., we conjecture that integral generalized permutohedra all have positive Ehrhart coefficients. Berline and Vergne construct a valuation that assigns values to faces of polytopes, which provides a…

Combinatorics · Mathematics 2017-10-17 Federico Castillo , Fu Liu

Let u and v be permutations on n letters, with u <= v in Bruhat order. A Bruhat interval polytope Q_{u,v} is the convex hull of all permutation vectors z = (z(1), z(2),...,z(n)) with u <= z <= v. Note that when u=e and v=w_0 are the…

Combinatorics · Mathematics 2015-06-11 Emmanuel Tsukerman , Lauren Williams

If $\mathcal{P}$ is a lattice polytope (i.e., $\mathcal{P}$ is the convex hull of finitely many integer points in $\mathbb{R}^d$), Ehrhart's famous theorem (1962) asserts that the integer-point counting function $|t \mathcal{P} \cap…

Combinatorics · Mathematics 2026-05-05 Matthias Beck , Thomas Kunze

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

In this note, we apply combinatorial techniques from our Ph.D. thesis to study how generalized permutohedra may be represented functionally on Parke-Tayor factors and related rational functions. In any functional representation of…

Combinatorics · Mathematics 2017-09-13 Nick Early

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