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Related papers: On the intersection of infinite matroids

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In 1960 Nash-Williams proved that an edge-connectivity of 2k is sufficient for a finite graph to have a k-arc-connected orientation. He then conjectured that the same is true for infinite graphs. In 2016, Thomassen, using his own results on…

Combinatorics · Mathematics 2024-08-29 Amena Assem

Bidirected graphs are a generalisation of directed graphs that arises in the study of undirected graphs with perfect matchings. Menger's famous theorem - the minimum size of a set separating two vertex sets $X$ and $Y$ is the same as the…

Combinatorics · Mathematics 2023-06-29 Nathan Bowler , Ebrahim Ghorbani , Florian Gut , Raphael W. Jacobs , Florian Reich

We present infinite sequences of excluded minors for both the class of lifted-graphic matroids and the class of frame matroids.

Combinatorics · Mathematics 2018-04-19 Rong Chen , Jim Geelen

Motivated by Lang-Vojta's conjecture, we show that the set of dominant rational self-maps of an algebraic variety over a number field with only finitely many rational points in any given number field is finite by combining Amerik's theorem…

Algebraic Geometry · Mathematics 2020-06-17 Ariyan Javanpeykar , Junyi Xie

In the 1990s, Kita--Yoshida and Cho--Matsumoto introduced intersection forms on the twisted (co)homologies of hyperplane arrangement complements. We give a closed combinatorial formula for these intersection pairings. We show that these…

Combinatorics · Mathematics 2025-08-05 Thomas Lam

Polat generalised Menger's theorem -- the maximum number of vertex-disjoint paths between two sets $A$ and $B$ equals the minimum size of an $A$-$B$ separator -- to ends of undirected graphs. In this paper we extend Menger's theorem to ends…

Combinatorics · Mathematics 2026-04-13 Florian Reich

Nash-Williams' Strong Immersion Conjecture states that graphs are well-quasi-ordered by the strong immersion relation. That is, given infinitely many graphs, one graph contains another graph as a strong immersion. In this paper we study the…

Combinatorics · Mathematics 2024-12-16 Chun-Hung Liu , Irene Muzi

To illustrate that the notion of convergence of submodular function sequences fits reasonably into the limit theory of graphs, we describe several classes of matroids and other submodular setfunctions for which convergence of appropriate…

Combinatorics · Mathematics 2025-07-22 Kristóf Bérczi , Márton Borbényi , László Lovász , László Márton Tóth

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

We prove that if nonlinear complex polynomials of the same degree have orbits with infinite intersection, then the polynomials have a common iterate. We also prove a special case of a conjectured dynamical analogue of the Mordell-Lang…

Number Theory · Mathematics 2009-11-13 Dragos Ghioca , Thomas J. Tucker , Michael E. Zieve

We give a short proof that every finite graph (or matroid) has a tree-decomposition that displays all maximal tangles. This theorem for graphs is a central result of the graph minors project of Robertson and Seymour and the extension to…

Combinatorics · Mathematics 2016-06-01 Johannes Carmesin

Suppose $A=k[X_1, X_2, \ldots, X_n]$ is a polynomial ring over a field $k$ and $I$ is an ideal in $A$. Then M. P. Murthy conjectured that $\mu(I)=\mu(I/I^2)$, where $\mu$ denotes the minimal number of generators. Recently, Fasel \cite{F}…

Commutative Algebra · Mathematics 2015-10-12 Satya Mandal

One characterization of binary matroids is that the symmetric difference of every pair of intersecting circuits is a disjoint union of circuits. This paper considers circuit-difference matroids, that is, those matroids in which the…

Combinatorics · Mathematics 2020-08-11 George Drummond , Tara Fife , Kevin Grace , James Oxley

Antimatroids were discovered by Dilworth in the context of lattices [4] and introduced by Edelman and Jamison as convex geometries in[5]. The author of the current paper independently discovered (possibly infinite) antimatroids in the…

Combinatorics · Mathematics 2012-01-17 Christian Joseph Altomare

Inspired by a recent result of Brakensiek et al. that symmetric tensor matroids and rigidity matroids are linked by matroid duality, we define abstract symmetric tensor matroids as a dual concept to abstract rigidity matroids and establish…

Combinatorics · Mathematics 2025-03-20 Bill Jackson , Shin-ichi Tanigawa

In this paper, we prove the existence portion of the Bertram-Feinberg-Mukai Conjecture for an infinite family of new cases using degeneration technique. This not only leads to a substantial improvement of known results but also develops…

Algebraic Geometry · Mathematics 2016-08-29 Naizhen Zhang

This is essentially an erratum, with some example to indicate inconsistencies. Suppose $A=k[X_1, X_2, \ldots, X_n]$ is a polynomial ring over a field $k$. The Complete Intersection conjecture states that, for any ideal $I$ in $A$,…

Commutative Algebra · Mathematics 2017-02-02 Satya Mandal

Whitney's 2-Isomorphism Theorem characterises when two graphs have isomorphic cycle matroids. We present an analogue of this theorem for graphs embedded in surfaces by characterising when two graphs in surface have isomorphic…

Combinatorics · Mathematics 2019-10-11 Iain Moffatt , Jaeseong Oh

Inspired by Kontsevich's graphic orbifold Euler characteristic we define a virtual Euler characteristic for any finite set of isomorphism classes of matroids of rank $r$. Our main result provides a simple formula for the virtual Euler…

Combinatorics · Mathematics 2026-02-05 Madeline Brandt , Juliette Bruce , Daniel Corey

We investigate the structure of intersecting error-correcting codes, with a particular focus on their connection to matroid theory. We establish properties and bounds for intersecting codes with the Hamming metric and illustrate how these…

Combinatorics · Mathematics 2026-02-16 Fabrizio Conca , Benjamin Jany , Alberto Ravagnani