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Abstract polytopes are combinatorial structures with distinctive geometric, algebraic, or topological characteristics, that generalize (the face lattice of) traditional polyhedra, polytopes or tessellations. Most research has focused on…

Combinatorics · Mathematics 2026-04-02 Isabel Hubard , Egon Schulte

The mutually enriching relationship between graphs and matroids has motivated discoveries in both fields. In this paper, we exploit the similar relationship between embedded graphs and delta-matroids. There are well-known connections…

Combinatorics · Mathematics 2019-03-04 Carolyn Chun , Iain Moffatt , Steven D. Noble , Ralf Rueckriemen

Given an undirected graph, the non-empty subgraph polytope is the convex hull of the characteristic vectors of pairs (F, S) where S is a non-empty subset of nodes and F is a subset of the edges with both endnodes in S. We obtain a strong…

Discrete Mathematics · Computer Science 2015-02-17 Michele Conforti , Volker Kaibel , Matthias Walter , Stefan Weltge

We introduce and study different compactifications of the moduli space of $n$ distinct weighted labeled points in a flag of affine spaces. We construct these spaces via the weighted and generalized Fulton-MacPherson compactifications of…

Algebraic Geometry · Mathematics 2024-11-12 Patricio Gallardo , Javier González-Anaya , José Luis González

Flag matroids are a rich family of Coxeter matroids that can be characterized using pairs of matroids that form a quotient. We consider a class of matroids called positroids, introduced by Postnikov, and utilize their combinatorial…

Combinatorics · Mathematics 2019-12-17 Carolina Benedetti , Anastasia Chavez , Daniel Tamayo

We study paving matroids, their realization spaces, and their closures, along with matroid varieties and circuit varieties. Within this context, we introduce three distinct methods for generating polynomials within the associated ideals of…

Algebraic Geometry · Mathematics 2026-03-24 Emiliano Liwski , Fatemeh Mohammadi

We characterize the quotients among lattice path matroids (LPMs) in terms of their diagrams. This characterization allows us to show that ordering LPMs by quotients yields a graded poset, whose rank polynomial has the Narayana numbers as…

Combinatorics · Mathematics 2024-01-17 Carolina Benedetti , Kolja Knauer

A matroid is a combinatorial structure that captures and generalizes the algebraic concept of linear independence under a broader and more abstract framework. Matroids are closely related with many other topics in discrete mathematics, such…

Combinatorics · Mathematics 2022-03-16 Gianira N. Alfarano , Karan Khathuria , Simran Tinani

The Topological Representation Theorem for (oriented) matroids states that every (oriented) matroid can be realized as the intersection lattice of an arrangement of codimension one homotopy spheres on a homotopy sphere. In this paper, we…

Combinatorics · Mathematics 2015-03-19 Matthew T. Stamps

The paper investigates connections between abstract polytopes and properly edge colored graphs. Given any finite n-edge-colored n-regular graph G, we associate to G a simple abstract polytope P_G of rank n, called the colorful polytope of…

Combinatorics · Mathematics 2012-03-26 Gabriela Araujo-Pardo , Isabel Hubard , Deborah Oliveros , Egon Schulte

We study two-step flag positroids $(P_1, P_2)$, where $P_1$ is a quotient of $P_{2}$. We provide a complete characterization of all two-step flag positroids that contain a uniform matroid, extending and completing a partial result by…

Combinatorics · Mathematics 2025-04-07 Zhixing Chen , Yumou Fei , Jiyang Gao , Yuxuan Sun , Yuchong Zhang

A greedoid is a generalization of a matroid allowing for more flexible analyses and modeling of combinatorial optimization problems. However, these structures decimate many matroid properties contributing to their pervasive nature. A…

Combinatorics · Mathematics 2026-01-15 Robert Streit , Vijay K. Garg

The classical matrix tree theorem relates the number of spanning trees of a connected graph with the product of the nonzero eigenvalues of its Laplacian matrix. The class of regular matroids generalizes that of graphical matroids, and a…

Combinatorics · Mathematics 2014-05-12 Aaron Dall , Julian Pfeifle

A toric variety is constructed from a lattice polytope. It is common in algebraic combinatorics to carry this way a notion of an algebraic property from the variety to the polytope. From the combinatorial point of view, one of the most…

Combinatorics · Mathematics 2020-05-19 Michał Lasoń , Mateusz Michałek

If $G$ is a looped graph, then its adjacency matrix represents a binary matroid $M_{A}(G)$ on $V(G)$. $M_{A}(G)$ may be obtained from the delta-matroid represented by the adjacency matrix of $G$, but $M_{A}(G)$ is less sensitive to the…

Combinatorics · Mathematics 2013-09-04 Robert Brijder , Hendrik Jan Hoogeboom , Lorenzo Traldi

Swartz proved that any matroid can be realized as the intersection lattice of an arrangement of codimension one homotopy spheres on a sphere. This was an unexpected extension from the oriented matroid case, but unfortunately the…

Combinatorics · Mathematics 2015-03-13 Alexander Engstrom

We extend the definition of coarse flag Hilbert--Poincar\'e series to matroids; these series arise in the context of local Igusa zeta functions associated to hyperplane arrangements. We study these series in the case of oriented matroids by…

Combinatorics · Mathematics 2025-05-21 Lukas Kühne , Joshua Maglione

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

The natural matroid of an integer polymatroid was introduced to show that a simple construction of integer polymatroids from matroids yields all integer polymatroids. As we illustrate, the natural matroid can shed much more light on integer…

Combinatorics · Mathematics 2024-08-07 Joseph E. Bonin , Carolyn Chun , Tara Fife

We define an independence system associated with simple graphs. We prove that the independence system is a matroid for certain families of graphs, including trees, with bases as minimal resolving sets. Consequently, the greedy algorithm on…

Combinatorics · Mathematics 2024-10-22 Usman Ali , Iffat Fida Hussain