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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

Let $EX[M_1\dots, M_k]$ denote the class of binary matroids with no minors isomorphic to $M_1, \dots, M_k$. In this paper we give a decomposition theorem for $EX[S_{10}, S_{10}^*]$, where $S_{10}$ is a certain 10-element rank-4 matroid. As…

Combinatorics · Mathematics 2014-05-21 Sandra Kingan

Rough sets are efficient for data pre-processing in data mining. As a generalization of the linear independence in vector spaces, matroids provide well-established platforms for greedy algorithms. In this paper, we apply rough sets to…

Artificial Intelligence · Computer Science 2012-09-26 Jingqian Wang , William Zhu

In this note we characterize tropical bases as sets of circuits that by orthogonality determine the set of cocircuits of a simple matroid. Furthermore, we show that any circuit, which itself is closed, must be contained in any tropical…

Combinatorics · Mathematics 2024-06-21 Winfried Hochstättler

In this sequel to "Foundations of matroids - Part 1", we establish several presentations of the foundation of a matroid in terms of small building blocks. For example, we show that the foundation of a matroid M is the colimit of the…

Combinatorics · Mathematics 2024-07-31 Matthew Baker , Oliver Lorscheid , Tianyi Zhang

We prove that every paving matroid that is an excluded minor of interval positroids can be reduced to one of three fundamental families of excluded minors of interval positroids by relaxing dependent hyperplanes. Using this result, we…

Combinatorics · Mathematics 2023-12-07 Hyungju Park

Sparse graphs and their associated matroids play an important role in rigidity theory, where they capture the combinatorics of generically rigid structures. We define a new family called {\bf graded sparse graphs}, arising from generically…

Combinatorics · Mathematics 2011-11-10 Audrey Lee , Ileana Streinu , Louis Theran

The class of 2-regular matroids is a natural generalisation of regular and near-regular matroids. We prove an excluded-minor characterisation for the class of 2-regular matroids. The class of 3-regular matroids coincides with the class of…

Combinatorics · Mathematics 2023-09-07 Nick Brettell , James Oxley , Charles Semple , Geoff Whittle

This note contributes to the structure theory of abstract rigidity matroids in general dimension. In the spirit of classical matroid theory, we prove several cryptomorphic characterizations of abstract rigidity matroids (in terms of…

Combinatorics · Mathematics 2015-03-13 Emanuele Delucchi , Tim Lindemann

A binary frame template is a device for creating binary matroids from graphic or cographic matroids. Such matroids are said to conform or coconform to the template. We introduce a preorder on these templates and determine the nontrivial…

Combinatorics · Mathematics 2020-06-02 Kevin Grace , Stefan H. M. van Zwam

Matroid is a generalization of many fundamental objects in combinatorial mathematics , and matroid intersection problem is a classical subject in combinatorial optimization . However , only the intersection of two matroids are well…

Combinatorics · Mathematics 2023-01-10 Tianyu Liu

We present an algebraic framework which simultaneously generalizes the notion of linear subspaces, matroids, valuated matroids, oriented matroids, and regular matroids. To do this, we first introduce algebraic objects called tracts which…

Combinatorics · Mathematics 2018-12-13 Matthew Baker , Nathan Bowler

We tackle the problem of a combinatorial classification of finite metric spaces via their fundamental polytopes, as suggested by Vershik in 2010. In this paper we consider a hyperplane arrangement associated to every split pseudometric and,…

Combinatorics · Mathematics 2022-03-28 Emanuele Delucchi , Linard Hoessly

The basis exchange axiom has been a driving force in the development of matroid theory. However, the axiom gives only a local characterization of the relation of bases, which is a major stumbling block to further progress, and providing a…

Combinatorics · Mathematics 2022-11-23 Kristóf Bérczi , Tamás Schwarcz

Vf-safe delta-matroids have the desirable property of behaving well under certain duality operations. Several important classes of delta-matroids are known to be vf-safe, including the class of ribbon-graphic delta-matroids, which is…

Combinatorics · Mathematics 2024-08-07 Joseph E Bonin , Carolyn Chun , Steven D Noble

Generalizing a well known theorem for finite matroids, we prove that for every (infinite) connected matroid M there is a unique tree T such that the nodes of T correspond to minors of M that are either 3-connected or circuits or cocircuits,…

Combinatorics · Mathematics 2015-06-08 Elad Aigner-Horev , Reinhard Diestel , Luke Postle

An excluded minor characterization for the class of binary signed-graphic matroids with graphic cocircuits is provided. In this report we present the necessary computations for the case analysis in the proof.

Combinatorics · Mathematics 2012-05-07 Konstantinos Papalamprou , Leonidas Pitsoulis

We classify all matroids with at most 8 elements that have the half-plane property, and we provide a list of some matroids on 9 elements that have, and that do not have the half-plane property. Furthermore, we prove that several classes of…

Combinatorics · Mathematics 2023-10-25 Mario Kummer , Büşra Sert

Matroid theory is often thought of as a generalization of graph theory. In this paper we propose an analogous correspondence between embedded graphs and delta-matroids. We show that delta-matroids arise as the natural extension of graphic…

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

Seymour's Splitter Theorem is a basic inductive tool for dealing with $3$-connected matroids. This paper proves a generalization of that theorem for the class of $2$-polymatroids. Such structures include matroids, and they model both sets…

Combinatorics · Mathematics 2017-06-27 James Oxley , Charles Semple , Geoff Whittle