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In this paper, we consider dynamic matroids, where elements can be inserted to or deleted from the ground set over time. The independent sets change to reflect the current ground set. As matroids are central to the study of many…

Data Structures and Algorithms · Computer Science 2026-02-10 Tijn de Vos , Mara Grilnberger

We generalize the 1/3-2/3 conjecture from partially ordered sets to antimatroids: we conjecture that any antimatroid has a pair of elements x,y such that x has probability between 1/3 and 2/3 of appearing earlier than y in a uniformly…

Combinatorics · Mathematics 2014-08-07 David Eppstein

We establish a connection between problems studied in rigidity theory and matroids arising from linear algebraic constructions like tensor products and symmetric products. A special case of this correspondence identifies the problem of…

Combinatorics · Mathematics 2026-03-04 Joshua Brakensiek , Manik Dhar , Jiyang Gao , Sivakanth Gopi , Matt Larson

We construct a family of independent sets for finite, atomic, and graded lattices, extending the well-known cryptomorphism between geometric lattices and matroids. This construction leads to an embedding theorem into geometric lattices that…

Combinatorics · Mathematics 2026-01-08 Or Raz

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

Given a root system $\mathsf{R}$, the vector system $\tilde{\mathsf{R}}$ is obtained by taking a representative $v$ in each antipodal pair $\{v, -v\}$. The matroid $M(\mathsf{R})$ is formed by all independent subsets of…

Combinatorics · Mathematics 2008-11-25 Mathieu Dutour Sikiric , Anna Felikson , Pavel Tumarkin

This paper deals with the problem of representing the matching independence system in a graph as the intersection of finitely many matroids. After characterizing the graphs for which the matching independence system is the intersection of…

Combinatorics · Mathematics 2007-05-23 Sandor P. Fekete , Robert T. Firla , Bianca Spille

In this work we present an algorithm to construct sparse-paving matroids over finite set $S$. From this algorithm we derive some useful bounds on the cardinality of the set of circuits of any Sparse-Paving matroids which allow us to prove…

Combinatorics · Mathematics 2018-10-18 B. Mederos , M. Takane , G. Tapia-Sanchez , B. Zavala

We address a specific case of the matroid intersection problem: given a set of graphs sharing the same set of vertices, select a minimum cycle basis for each graph to maximize the size of their intersection. We provide a comprehensive…

Computational Complexity · Computer Science 2024-04-29 Dimitri Watel , Marc-Antoine Weisser , Dominique Barth , Ylène Aboulfath , Thierry Mautor

Rough set theory is a useful tool to deal with uncertain, granular and incomplete knowledge in information systems. And it is based on equivalence relations or partitions. Matroid theory is a structure that generalizes linear independence…

Artificial Intelligence · Computer Science 2012-10-24 Yanfang Liu , William Zhu

Frame matroids and lifted-graphic matroids are two interesting generalizations of graphic matroids. Here we introduce a new generalization, {\em quasi-graphic matroids}, that unifies these two existing classes. Unlike frame matroids and…

Combinatorics · Mathematics 2017-04-25 Jim Geelen , Bert Gerards , Geoff Whittle

We establish a strong, geometric lower bound on the (sequential) topological complexity of the unordered configuration spaces of a general graph. As an application, we show that, for most graphs, the topological complexity eventually…

Algebraic Topology · Mathematics 2026-02-05 Ben Knudsen

Let $\mathcal{P}$ be a set of $n=2m+1$ points in the plane in general position. We define the graph $GM_\mathcal{P}$ whose vertex set is the set of all plane matchings on $\mathcal{P}$ with exactly $m$ edges. Two vertices in…

Computational Geometry · Computer Science 2024-10-10 Oswin Aichholzer , Anna Brötzner , Daniel Perz , Patrick Schnider

We study point-line configurations, their minimal matroids, and their associated circuit varieties. We present an algorithm for identifying the minimal matroids of these configurations with respect to dependency order, or equivalently, the…

Combinatorics · Mathematics 2025-02-04 Emiliano Liwski , Fatemeh Mohammadi

We give an upper bound on the number of perfect matchings in simple graphs with a given number of vertices and edges. We apply this result to give an upper bound on the number of 2-factors in a directed complete bipartite balanced graph on…

Combinatorics · Mathematics 2014-08-01 M. Aaghabali , S. Akbari , S. Friedland , K. Markstrom , Z. Tajfirouz

Given two finite matroids on the same ground set, a celebrated result of Edmonds says that the ground set can be partitioned into two disjoint subsets in a manner that there is a common independent set in both matroids whose intersection…

Combinatorics · Mathematics 2025-01-27 Irfan Alam

We prove that every infinite sequence of skew-symmetric or symmetric matrices M_1, M_2, ... over a fixed finite field must have a pair M_i, M_j (i<j) such that M_i is isomorphic to a principal submatrix of the Schur complement of a…

Combinatorics · Mathematics 2014-03-26 Sang-il Oum

The number of homomorphisms from a finite graph $F$ to the complete graph $K_n$ is the evaluation of the chromatic polynomial of $F$ at $n$. Suitably scaled, this is the Tutte polynomial evaluation $T(F;1-n,0)$ and an invariant of the cycle…

Combinatorics · Mathematics 2016-02-25 Andrew Goodall , Guus Regts , Lluis Vena

We study the fixed point set in the ideal boundary of a parabolic isometry of a proper CAT(0)-space. We show that the radius of the fixed point set is at most pi/2, and study its centers. As a consequence, we prove that the set of fixed…

Differential Geometry · Mathematics 2007-05-23 Koji Fujiwara , Koichi Nagano , Takashi Shioya

We introduce ideas that complement the many known connections between polymatroids and graph coloring. Given a hypergraph that satisfies certain conditions, we construct polymatroids, given as rank functions, that can be written as sums of…

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