English
Related papers

Related papers: A combinatorial formula for the Ehrhart $h^{*}$-ve…

200 papers

Hypersimplices are well-studied objects in combinatorics, optimization, and representation theory. For each hypersimplex, we define a new family of subpolytopes, called r-stable hypersimplices, and show that a well-known regular unimodular…

Combinatorics · Mathematics 2016-03-17 Benjamin Braun , Liam Solus

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

It is proved that a certain symmetric sequence of nonnegative integers arising in the enumeration of magic squares of given size n by row sums or, equivalently, in the generating function of the Ehrhart polynomial of the polytope of doubly…

Combinatorics · Mathematics 2007-05-23 Christos A. Athanasiadis

This paper introduces a new and simple statistic on noncrossing partitions that expresses each coordinate of the toric $h$-vector of a cubical complex, written in the basis of the Adin $h$-vector entries, as the total weight of all…

Combinatorics · Mathematics 2013-02-21 Sarah Birdsong , Gábor Hetyei

We give a simple formula for the number of hypertrees with $k$ hyperedges of given sizes and $n+1$ labelled vertices with prescribed degrees. A slight generalization of this formula counts labelled bipartite trees with prescribed degrees in…

Combinatorics · Mathematics 2011-02-15 Roland Bacher

Let $H^{\infty}(E)$ be a non commutative Hardy algebra, associated with a $W^*$-correspondence $E$. In this paper we construct factorizations of inner-outer type of the elements of $H^{\infty}(E)$ represented via the induced representation,…

Operator Algebras · Mathematics 2015-03-31 Leonid Helmer

The notion of Ehrhart tensor polynomials, a natural generalization of the Ehrhart polynomial of a lattice polytope, was recently introduced by Ludwig and Silverstein. We initiate a study of their coefficients. In the vector and matrix…

Combinatorics · Mathematics 2017-06-07 Sören Berg , Katharina Jochemko , Laura Silverstein

We classify all the possible $delta$-vectors of d-dimensional integral convex polytopes whose volumes are less than or equal to 3/(d!).

Combinatorics · Mathematics 2009-04-24 Takayuki Hibi , Akihiro Higashitani , Yuuki Nagazawa

Alcoved polytopes are convex polytopes, which are the closure of a union of alcoves in an affine Coxeter arrangement. They are rational polytopes and, therefore, have Ehrhart quasipolynomials. Here we describe a method for computing the…

Combinatorics · Mathematics 2025-04-23 Elisabeth Bullock , Yuhan Jiang

For an $n$-dimensional lattice simplex $\Delta_{(1,\mathbf{q})}$ with vertices given by the standard basis vectors and $-\mathbf{q}$ where $\mathbf{q}$ has positive entries, we investigate when the Ehrhart $h^*$-polynomial for…

Combinatorics · Mathematics 2018-07-20 Benjamin Braun , Fu Liu

We study the Ehrhart theory of hypersimplices of type C, as introduced by Lam and Postnikov for general crystallographic root systems. The $h^*$-polynomials of classical hypersimplices are known to relate to various Eulerian statistics on…

Combinatorics · Mathematics 2025-04-08 Antoine Abram , Jose Bastidas

The purpose of this note is to supply an upper and a lower bound (which are in general sharp) for the $h$-vector of a level algebra which is relatively compressed with respect to any arbitrary level algebra $A$. The useful concept of…

Commutative Algebra · Mathematics 2007-06-13 Fabrizio Zanello

We consider the Ehrhart polynomial of hypersimplices. It is proved that these polynomials have positive coefficients and we give a combinatorial formula for each of them. This settles a problem posed by Stanley and also proves that uniform…

Combinatorics · Mathematics 2020-11-23 Luis Ferroni

In [7], Higashitani, Kummer, and Micha{\l}ek pose a conjecture about the symmetric edge polytopes of complete multipartite graphs and confirm it for a number of families in the bipartite case. We confirm that conjecture for a number of new…

Combinatorics · Mathematics 2024-04-03 Max Kölbl

We establish new lower bounds for the Tur\'an and Zarankiewicz numbers of certain apex partite hypergraphs. Given a $(d-1)$-partite $(d-1)$-uniform hypergraph $\mathcal{H}$, let $\mathcal{H}(k)$ be the $d$-partite $d$-uniform hypergraph…

Combinatorics · Mathematics 2025-10-10 Qiyuan Chen , Hong Liu , Ke Ye

We give a combinatorial formula for the Ehrhart coefficients of a certain class of weighted multi-hypersimplices. In a special case, where these polytopes coincide with the base polytope of the panhandle matroid $\textrm{Pan}_{k,n-2,n}$, we…

Combinatorics · Mathematics 2023-12-13 Daniel McGinnis

We propose a new representation of $k$-partite, $k$-uniform hypergraphs, that is, a hypergraph with a partition of vertices into $k$ parts such that each hyperedge contains exactly one vertex of each type; we call them $k$-hypergraphs for…

Combinatorics · Mathematics 2025-02-19 Oksana Firman , Joachim Spoerhase

The (n,k)-hypersimplex is the convex hull of all 0/1-vectors of length n with coordinate sum k. We explicitly determine the extension complexity of all hypersimplices as well as of certain classes of combinatorial hypersimplices. To that…

Metric Geometry · Mathematics 2017-02-28 Francesco Grande , Arnau Padrol , Raman Sanyal

The half-open hypersimplex $\Delta'_{n,k}$ consists of those $x = (x_{1}, \ldots, x_{n}) \in[0,1]^n$ with $k-1<x_1+\cdots+x_n\le k$, where $0 < k \leq n$. The $f$-vector of a half-open hypersimplex and related generating functions are…

Combinatorics · Mathematics 2016-02-02 Takayuki Hibi , Nan Li , Hidefumi Ohsugi

The univariate Ehrhart and $h^*$-polynomials of lattice polytopes have been widely studied. We describe methods from toric geometry for computing multivariate versions of volume, Ehrhart and $h^*$-polynomials of lattice polytropes, which…

Combinatorics · Mathematics 2023-03-08 Marie-Charlotte Brandenburg , Sophia Elia , Leon Zhang