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Related papers: The polytope of all matroids

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We give explicit recursive constructions for the polytope of all matroids $\Omega_{r,n}$ in ranks 2 and 3 for all ground set sizes. This polytope was introduced in recent work by Ferroni and Fink as a tool for checking positivity…

Combinatorics · Mathematics 2026-05-13 Narayan Collins , Victoria Schleis

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

A $q$-rank function is a real-valued function defined on the subspace lattice that is non-negative, upper bounded by the dimension function, non-drecreasing, and satisfies the submodularity law. Each such function corresponds to the rank…

Combinatorics · Mathematics 2025-05-27 Gianira N. Alfarano , Sebastian Degen

For a lattice polytope $P$, the rank of $P$ is defined by $F-(\dim P+1)$, where $F$ is the number of facets of $P$. In this paper, we study matroid polytopes with small rank. More precisely, we characterize matroid independence polytopes…

Combinatorics · Mathematics 2025-03-31 Masato Konoike , Koji Matsushita

Luis Ferroni and Alex Fink recently introduced a polytope of all unlabeled matroids of rank $r$ on $n$ elements, and they showed that the vertices of this polytope come from matroids that can be characterized by maximizing a sequence of…

Combinatorics · Mathematics 2025-12-23 Joseph E. Bonin

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 provide a full classification of all families of matroids that are closed under duality and minors, and for which the Tutte polynomial is a universal valuative invariant. There are four inclusion-wise maximal families, two of which are…

Combinatorics · Mathematics 2025-02-10 Luis Ferroni , Benjamin Schröter

In this paper, we give a formula for the number of lattice points in the dilations of Schubert matroid polytopes. As applications, we obtain the Ehrhart polynomials of uniform and minimal matroids as special cases, and give a recursive…

Combinatorics · Mathematics 2022-12-07 Neil J. Y. Fan , Yao Li

Morphisms of matroids are combinatorial abstractions of linear maps and graph homomorphisms. We introduce the notion of basis for morphisms of matroids, and show that its generating function is strongly log-concave. As a consequence, we…

Combinatorics · Mathematics 2020-04-02 Christopher Eur , June Huh

This article is a survey of matroid theory aimed at algebraic geometers. Matroids are combinatorial abstractions of linear subspaces and hyperplane arrangements. Not all matroids come from linear subspaces; those that do are said to be…

Algebraic Geometry · Mathematics 2014-09-12 Eric Katz

We associate to every matroid M a polynomial with integer coefficients, which we call the Kazhdan-Lusztig polynomial of M, in analogy with Kazhdan-Lusztig polynomials in representation theory. We conjecture that the coefficients are always…

Combinatorics · Mathematics 2016-07-04 Ben Elias , Nicholas Proudfoot , Max Wakefield

In this paper we investigate the number of integer points lying in dilations of lattice path matroid polytopes. We give a characterization of such points as polygonal paths in the diagram of the lattice path matroid. Furthermore, we prove…

Combinatorics · Mathematics 2017-10-26 Kolja Knauer , Leonardo Martínez-Sandoval , Jorge Luis Ramírez Alfonsín

Given a finite quiver (directed graph) without loops and multiedges, the convex hull of the column vector of the incidence matrix is called the directed edge polytope and is an interesting example of lattice polytopes. In this paper, we…

Combinatorics · Mathematics 2022-03-29 Yasuhide Numata , Yusuke Takahashi , Dai Tamaki

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

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

We use the geometry of the stellahedral toric variety to study matroids. We identify the valuative group of matroids with the cohomology ring of the stellahedral toric variety, and show that valuative, homological, and numerical equivalence…

Algebraic Geometry · Mathematics 2023-09-08 Christopher Eur , June Huh , Matt Larson

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 present a definition of oriented Lagrangian symplectic matroids and their representations. Classical concepts of orientation and this extension may both be thought of as stratifications of thin Schubert cells into unions of…

Combinatorics · Mathematics 2007-05-23 Richard F. Booth , Alexandre V. Borovik , Israel M. Gelfand , Neil White

We decompose the indicator function of each $(a, b)$-Catalan matroid polytope as a weighted sum of indicator function of matroid polytopes that correspond to direct sums of uniform matroids. Catalan matroids lie in the interior of the…

Combinatorics · Mathematics 2025-10-10 Yiming Chen , Yao Li , Ming Yao

We study an operation in matroid theory that allows one to transition a given matroid into another with more bases via relaxing a \emph{stressed subset}. This framework provides a new combinatorial characterization of the class of split…

Combinatorics · Mathematics 2024-09-12 Luis Ferroni , Benjamin Schröter
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