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Related papers: Matroid polytopes and their volumes

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The Tutte polynomial for matroids is not directly applicable to polymatroids. For instance, deletion-contraction properties do not hold. We construct a polynomial for polymatroids which behaves similarly to the Tutte polynomial of a…

Combinatorics · Mathematics 2016-04-05 Amanda Cameron , Alex Fink

Regular semisimple Hessenberg varieties are subvarieties of the flag variety $\mathrm{Flag}(\mathbb{C}^n)$ arising naturally in the intersection of geometry, representation theory, and combinatorics. Recent results of…

Algebraic Geometry · Mathematics 2019-10-08 Megumi Harada , Tatsuya Horiguchi , Mikiya Masuda , Seonjeong Park

Mirkovi\'c-Vilonen (MV) polytopes are a class of generalized permutahedra originating from geometric representation theory. In this paper we study MV polytopes coming from matroid polytopes, flag matroid polytopes, Bruhat interval…

Combinatorics · Mathematics 2023-11-29 Mario Sanchez

We produce the first regular unimodular triangulation of an arbitrary matroid base polytope. We then extend our triangulation to integral generalized permutahedra. Prior to this work it was unknown whether each matroid base polytope…

Combinatorics · Mathematics 2024-04-05 Spencer Backman , Gaku Liu

This note is a comment to the paper by D.R.Heath-Brown and B.Z.Moroz (Math Proc. Camb. Phil. Soc. 125 (1999)). That paper concerns with the projective surface $S$ in $\mathbb{P}^{3}$ defined by the equation $x_{1}x_{2}x_{3}=x_{4}^{3}$. It…

Metric Geometry · Mathematics 2007-05-23 Anna Felikson , Pavel Tumarkin

Brion's Formula realizes the Laurent polynomial of lattice points in a lattice polytope P as the sum of rational functions associated to the vertices of P. In this paper, we consider the special case where P is a generalized permutohedron.…

Combinatorics · Mathematics 2026-05-06 Matthias Beck , Caroline Klivans , Dustin Ross

In the paper the foundation of the $k$-orbit theory is developed. The theory opens a new simple way to the investigation of groups and multidimensional symmetries. The relations between combinatorial symmetry properties of a $k$-orbit and…

General Mathematics · Mathematics 2007-05-23 Aleksandr Golubchik

We initiate the study of a class of polytopes, which we coin polypositroids, defined to be those polytopes that are simultaneously generalized permutohedra (or polymatroids) and alcoved polytopes. Whereas positroids are the matroids arising…

Combinatorics · Mathematics 2020-10-15 Thomas Lam , Alexander Postnikov

For a polytope we define the {\em flag polynomial}, a polynomial in commuting variables related to the well-known flag vector and describe how to express the the flag polynomial of the Minkowski sum of $k$ standard simplices in a direct and…

Combinatorics · Mathematics 2010-07-01 Geir Agnarsson

This dissertation presents new results on three different themes all related to matroid polytopes. First we investigate properties of Ehrhart polynomials of matroid polytopes, independence matroid polytopes, and polymatroids. We prove that…

Combinatorics · Mathematics 2009-05-28 David C. Haws

Generalizing polynomials previously studied in the context of linear codes, we define weight polynomials and an enumerator for a matroid $M$. Our main result is that these polynomials are determined by Betti numbers associated with graded…

Combinatorics · Mathematics 2015-11-13 Trygve Johnsen , Jan Roksvold , Hugues Verdure

Let M to be a matroid defined on a finite set E. A subset L of E is locked in M if L is 2-connected in M, the complement of L is 2-connected in the dual M*, and min{r(L), r*(complement of L)} is greater than 1. In this paper, we prove that…

Combinatorics · Mathematics 2016-12-22 Brahim Chaourar

We prove that the Gromov width of coadjoint orbits of the symplectic group is at least equal to the upper bound known from the works of Zoghi and Caviedes. This establishes the actual Gromov width. Our work relies on a toric degeneration of…

Symplectic Geometry · Mathematics 2018-04-25 Iva Halacheva , Milena Pabiniak

We use the equivariant cohomology ring of the permutohedral variety to study matroids and their invariants. Investigating the pushforward of matroid Chern classes defined by A. Berget, C. Eur, H. Spink and D. Tseng to the product space…

Algebraic Geometry · Mathematics 2025-09-25 Mario Bauer , Matěj Doležálek , Magdaléna Mišinová , Semen Słobodianiuk , Julian Weigert

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

We show the existence of a polynomial-size extended formulation for the base polytope of a $(k,\ell)$-sparsity matroid. For an undirected graph $G=(V,E)$, the size of the formulation is $O(|V||E|)$ when $k \geq \ell$ and $O(|V|^2 |E|)$ when…

Combinatorics · Mathematics 2014-03-31 Satoru Iwata , Naoyuki Kamiyama , Naoki Katoh , Shuji Kijima , Yoshio Okamoto

This is both an expository and research paper where we advocate a systematic study of continuous analogues of finite partially ordered sets, convex polytopes, oriented matroids, arrangements of subspaces, finite simplicial complexes, and…

Combinatorics · Mathematics 2016-03-29 Rade T. Živaljević

For a graph embedded into a surface, we relate many combinatorial parameters of the cycle matroid of the graph and the bond matroid of the dual graph with the topological parameters of the embedding. This will give an expression of the…

Combinatorics · Mathematics 2015-03-17 R. Askanazi , S. Chmutov , C. Estill , J. Michel , P. Stollenwerk

The free sum is a basic geometric operation among convex polytopes. This note focuses on the relationship between the normalized volume of the free sum and that of the summands. In particular, we show that the normalized volume of the free…

Combinatorics · Mathematics 2019-03-15 Tianran Chen , Robert Davis

Following Britz, Johnsen, Mayhew and Shiromoto, we consider demi\-ma\-troids as a(nother) natural generalization of matroids. As they have shown, demi\-ma\-troids are the appropriate combinatorial objects for studying Wei's duality. Our…

Combinatorics · Mathematics 2019-07-24 Jose Martinez-Bernal , Miguel A. Valencia-Bucio , Rafael H. Villarreal