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Related papers: Matroid polytopes with small rank

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The rank of a $d$-dimensional polytope $P$ is defined by $F-(d+1)$, where $F$ denotes the number of facets of $P$. In this paper, We focus on the toric rings of $(0,1)$-polytopes with small rank. We study their normality, the…

Combinatorics · Mathematics 2023-03-24 Koji Matsushita

The weak-map order on the matroid base polytopes is the partial order defined by inclusion. Lucas proved that the base polytope of no binary matroid includes the base polytope of a connected matroid. A matroid base polytope is said to be…

Combinatorics · Mathematics 2012-03-26 Kenji Kashiwabara

It is possible to write the indicator function of any matroid polytope as an integer combination of indicator functions of Schubert matroid polytopes. In this way, every matroid on $n$ elements of rank $r$ can be thought of as a lattice…

Combinatorics · Mathematics 2025-08-14 Luis Ferroni , Alex Fink

Fix two lattice paths $P$ and $Q$ from $(0,0)$ to $(m,r)$ that use East and North steps with $P $ never going above $Q$. Bonin et al. show that the lattice paths that go from $(0,0)$ to $(m,r)$ and remain bounded by $P$ and $Q$ can be…

Combinatorics · Mathematics 2012-12-27 Hoda Bidkhori

This paper initiates the explicit study of face numbers of matroid polytopes and their computation. We prove that, for the large class of split matroid polytopes, their face numbers depend solely on the number of cyclic flats of each rank…

Combinatorics · Mathematics 2025-07-02 Luis Ferroni , Benjamin Schröter

We characterize the edges of two classes of $0/1$-polytopes. The first class corresponds to the stable set polytope of a graph $G$ and includes chain polytopes of posets, some instances of matroid independence polytopes, as well as…

Combinatorics · Mathematics 2021-10-27 Farid Aliniaeifard , Carolina Benedetti , Nantel Bergeron , Shu Xiao Li , Franco Saliola

The positive semidefinite (psd) rank of a polytope is the smallest $k$ for which the cone of $k \times k$ real symmetric psd matrices admits an affine slice that projects onto the polytope. In this paper we show that the psd rank of a…

Optimization and Control · Mathematics 2013-08-01 João Gouveia , Richard Z. Robinson , Rekha R. Thomas

We prove that the ranks of the subsets and the activities of the bases of a matroid define valuations for the subdivisions of a matroid polytope into smaller matroid polytopes.

Combinatorics · Mathematics 2019-08-15 Federico Ardila , Alex Fink , Felipe Rincón

In this paper, we study flag structures of matroid base polytopes. We describe faces of matroid base polytopes in terms of matroid data, and give conditions for hyperplane splits of matroid base polytopes. Also, we show how the cd-index of…

Combinatorics · Mathematics 2009-01-30 Sangwook Kim

A lattice path matroid is a transversal matroid corresponding to a pair of lattice paths on the plane. A matroid base polytope is the polytope whose vertices are the incidence vectors of the bases of the given matroid. In this paper, we…

Combinatorics · Mathematics 2017-01-03 Suhyung An , JiYoon Jung , Sangwook Kim

A classification of discrete polymatroids whose independence polytopes are reflexive will be presented.

Combinatorics · Mathematics 2023-02-27 Jürgen Herzog , Takayuki Hibi

Polymatroids can be considered as "fractional matroid" where the rank function is not required to be integer valued. Many, but not every notion in matroid terminology translates naturally to polymatroids. Defining cyclic flats of a…

Combinatorics · Mathematics 2019-10-15 Laszlo Csirmaz

The positive semidefinite (psd) rank of a polytope is the size of the smallest psd cone that admits an affine slice that projects linearly onto the polytope. The psd rank of a d-polytope is at least d+1, and when equality holds we say that…

Combinatorics · Mathematics 2016-07-26 João Gouveia , Kanstanstin Pashkovich , Richard Z. Robinson , Rekha R. Thomas

Neighborly polytopes are those that maximize the number of faces in each dimension among all polytopes with the same number of vertices. Despite their extremal properties they form a surprisingly rich class of polytopes, which has been…

Combinatorics · Mathematics 2015-01-30 Hiroyuki Miyata , Arnau Padrol

A matroid base polytope is a polytope in which each vertex has 0,1 coordinates and each edge is parallel to a difference of two coordinate vectors. Matroid base polytopes are described combinatorially by integral submodular functions on a…

Combinatorics · Mathematics 2025-11-19 Jonah Berggren , Jeremy L. Martin , José A. Samper

A positroid is a special case of a realizable matroid that arose from the study of the totally nonnegative part of the Grassmannian by Postnikov. In this paper, we study the facets of its matroid polytope and the independent set polytope.…

Combinatorics · Mathematics 2021-08-17 Suho Oh , David Xiang

We specify what is meant for a polytope to be reconstructible from its graph or dual graph. And we introduce the problem of class reconstructibility, i.e., the face lattice of the polytope can be determined from the (dual) graph within a…

Combinatorics · Mathematics 2022-08-05 Guillermo Pineda-Villavicencio , Benjamin Schröter

2-level polytopes naturally appear in several areas of pure and applied mathematics, including combinatorial optimization, polyhedral combinatorics, communication complexity, and statistics. In this paper, we present a study of some 2-level…

Combinatorics · Mathematics 2017-12-15 Manuel Aprile , Alfonso Cevallos , Yuri Faenza

We are interested in expanding our understanding of symplectic matroids by exploring the properties of a class of symplectic matroids with a "lattice of flats". Taking a well-behaved family of subdivisions of the cross polytope we obtain a…

Combinatorics · Mathematics 2026-01-08 Or Raz

In this paper we highlight some enumerative results concerning matroids of low rank and prove the tail-ends of various sequences involving the number of matroids on a finite set to be log-convex. We give a recursion for a new, slightly…

Combinatorics · Mathematics 2007-05-23 W. M. B. Dukes
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