English
Related papers

Related papers: On the connected blocks polytope

200 papers

The Birkhoff polytope, defined to be the convex hull of $n\times n$ permutation matrices, is a well studied polytope in the context of the Ehrhart theory. This polytope is known to have many desirable properties, such as the Gorenstein…

Combinatorics · Mathematics 2019-06-06 Florian Kohl , McCabe Olsen

We consider, for complete bipartite graphs, the convex hulls of characteristic vectors of all matchings, extended by a binary entry indicating whether the matching contains two specific edges. These polytopes are associated to the quadratic…

Discrete Mathematics · Computer Science 2019-04-09 Matthias Walter

This article studies a large, general class of orthogonal polytopes which we may call "generic orthotopes". These objects emerged from a desire to represent a Coxeter complex by an orthogonal polytope that is particularly nice with respect…

Combinatorics · Mathematics 2022-10-24 David Richter

In this paper, we give a criterion of the nearly Gorenstein property of the Ehrhart ring of the stable set polytope of an h-perfect graph: the Ehrhart ring of the stable set polytope of an h-perfect graph $G$ with connected components…

Commutative Algebra · Mathematics 2022-01-25 Mitsuhiro Miyazaki

We classify connected graphs $G$ whose binomial edge ideal is Gorenstein. The proof uses methods in prime characteristic.

Commutative Algebra · Mathematics 2021-02-23 René González-Martínez

Starting from any finite simple graph, one can build a reflexive polytope known as a symmetric edge polytope. The first goal of this paper is to show that symmetric edge polytopes are intrinsically matroidal objects: more precisely, we…

Combinatorics · Mathematics 2023-07-12 Alessio D'Alì , Martina Juhnke-Kubitzke , Melissa Koch

In this paper we give several criteria for the edge polytope of a fundamental FHM-graph to possess a regular unimodular triangulation in terms of some simple data of the the graph. We further apply our criteria to several examples of graphs…

Combinatorics · Mathematics 2016-12-02 Ginji Hamano

We identify a family of $O(|E(G)|^2)$ nontrivial facets of the connected matching polytope of a graph $G$, that is, the convex hull of incidence vectors of matchings in $G$ whose covered vertices induce a connected subgraph. Accompanying…

Combinatorics · Mathematics 2023-10-24 Phillippe Samer

Let $I_G$ be the binomial edge ideal on the generic 2 x n - Hankel matrix associated with a closed graph $G$ on the vertex set [n]. We characterize the graphs $G$ for which $I_G$ has maximal regularity and is Gorenstein.

Commutative Algebra · Mathematics 2015-12-02 Ahmet Dokuyucu , Ajdin Halilovic , Rida Irfan

The perfectly matchable subgraph polytope of a graph is a (0,1)-polytope associated with the vertex sets of matchings in the graph. In this paper, we study algebraic properties (compressedness, Gorensteinness) of the toric rings of…

Combinatorics · Mathematics 2023-07-18 Kenta Mori

Graph polytopes arising from vertex-weighted graphs were first introduced by B\'ona, Ju, and Yoshida. We prove a conjecture stating that for any simple connected graph, the numerator polynomial of the Ehrhart series of its graph polytope is…

Combinatorics · Mathematics 2026-04-13 Feihu Liu

A level graph is the data of a pair $(G,\pi)$ consisting of a finite graph $G$ and an ordered partition $\pi$ on the set of vertices of $G$. To each level graph on $n$ vertices we associate a polytope in $\mathbb R^n$ called its residue…

Combinatorics · Mathematics 2024-10-18 Omid Amini , Eduardo Esteves , Eduardo Garcez

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 $k$-linked if, for every…

Combinatorics · Mathematics 2019-09-30 Hoa Thi Bui , Guillermo Pineda-Villavicencio , Julien Ugon

We introduce the cohomological blow up of a graded Artinian Gorenstein (AG) algebra along a surjective map, which we term BUG (Blow Up Gorenstein) for short. This is intended to translate to an algebraic context the cohomology ring of a…

Commutative Algebra · Mathematics 2021-09-14 Anthony Iarrobino , Pedro Macias Marques , Chris McDaniel , Alexandra Seceleanu , Junzo Watanabe

We study a symmetry problem for the $h$-polynomials of edge rings of bipartite graphs. Let $G$ be a bipartite graph and write $h(\mathbb{k}[G];t)=h_0+h_1t+\cdots+h_st^s$. We prove that if $\Bbbk[G]$ is pseudo-Gorenstein and $h_1=h_{s-1}$,…

Commutative Algebra · Mathematics 2026-05-28 Yuta Hatasa

In Ehrhart theory, the $h^*$-vector of a rational polytope often provide insights into properties of the polytope that may be otherwise obscured. As an example, the Birkhoff polytope, also known as the polytope of real doubly-stochastic…

Combinatorics · Mathematics 2015-04-28 Robert Davis

(Partial) Gorenstein silting modules are introduced and investigated. It is shown that for finite dimensional algebras of finite CM-type, partial Gorenstein silting modules are in bijection with {\tau}_G-rigid modules; Gorenstein silting…

Representation Theory · Mathematics 2022-09-02 Nan Gao , Jing Ma , Chi-Heng Zhang

Given any polytope $P$ and any generic linear functional ${\bf c} $, one obtains a directed graph $G(P,{\bf c})$ from the 1-skeleton of $P$ by orienting each edge $e(u,v)$ from $u$ to $v$ for ${\bf c} (u) < {\bf c} ( v)$. For $P$ a simple…

Combinatorics · Mathematics 2023-08-10 Patricia Hersh

In this paper, we give a criterion of the Gorenstein property of the Ehrhart ring of the stable set polytope of an h-perfect graph: the Ehrhart ring of the stable set polytope of an h-perfect graph $G$ is Gorenstein if and only if (1) sizes…

Combinatorics · Mathematics 2020-08-18 Mitsuhiro Miyazaki

Symmetric edge polytopes are lattice polytopes associated with finite simple graphs that are of interest in both theory and applications. We investigate the facet structure of symmetric edge polytopes for various models of random graphs.…

Combinatorics · Mathematics 2024-02-14 Benjamin Braun , Kaitlin Bruegge , Matthew Kahle