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Related papers: On the intersection of infinite matroids

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We characterize 2-dimensional complexes associated canonically with basis graphs of matroids as simply connected triangle-square complexes satisfying some local conditions. This proves a version of a (disproved) conjecture by Stephen Maurer…

Combinatorics · Mathematics 2018-12-10 Jérémie Chalopin , Victor Chepoi , Damian Osajda

We generalize the well-studied notion of a modular pair of a finite matroid to arbitrary families of sets in infinite matroids, and use it to develop the theory of infinite matroids in several as-yet-unexplored areas. Our results include a…

Combinatorics · Mathematics 2026-04-23 Mattias Ehatamm , Peter Nelson , Fernanda Rivera Omana

In this thesis, we study nearly finitary matroids by introducing new definitions and prove various properties of nearly finitary matroids. In 2010, an axiom system for infinite matroids was proposed by Bruhn et al. We use this axiom system…

Combinatorics · Mathematics 2019-06-13 Patrick Tam

This sequel to our paper (Infinite gammoids, 2014) considers minors and duals of infinite gammoids. We prove that a class of gammoids definable by digraphs not containing a certain type of substructure, called an outgoing comb, is…

Combinatorics · Mathematics 2014-11-11 Seyed Hadi Afzali Borujeni , Hiu Fai Law , Malte Müller

Thin sums matroids were introduced to extend the notion of representability to non-finitary matroids. We give a new criterion for testing when the thin sums construction gives a matroid. We show that thin sums matroids over thin families…

Combinatorics · Mathematics 2012-04-30 Hadi Afzali , Nathan Bowler

Let $G$ be a relatively hyperbolic group that admits a decomposition into a finite graph of relatively hyperbolic groups structure with quasi-isometrically (qi) embedded condition. We prove that the set of conjugates of all the vertex and…

Group Theory · Mathematics 2019-12-06 Swathi Krishna

Solving a problem of Diestel and Pott, we construct a large class of infinite matroids. These can be used to provide counterexamples against the natural extension of the Well-quasi-ordering-Conjecture to infinite matroids and to show that…

Combinatorics · Mathematics 2013-01-28 Nathan Bowler , Johannes Carmesin

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

Over a commutative Noetherian ring, we show that the Auslander-Reiten conjecture holds true for the class of (finitely generated) modules whose dual has finite complete intersection dimension. We provide another result that validates the…

Commutative Algebra · Mathematics 2026-03-16 Dipankar Ghosh , Mouma Samanta

In 1999 Merino and Welsh conjectured that evaluations of the Tutte polynomial of a graph satisfy an inequality. In this short article we show that the conjecture generalized to matroids holds for the large class of all split matroids by…

Combinatorics · Mathematics 2023-09-11 Luis Ferroni , Benjamin Schröter

The disproved Nash Williams conjecture states that every 4-regular 4-connected graph has a hamiltonian cycle. We show that a modification of this conjecture is equivalent to the Dominating Cycle Conjecture.

Combinatorics · Mathematics 2015-08-12 Arthur Hoffmann-Ostenhof

In this paper we prove Ahlswede- Khachatrian conjecture~\cite{1} up to finite number of cases, which can be checked using modern computers. From this conjecture follows conjecture from~\cite{2} and Manickam-Mikl\'{o}s-Singhi conjecture.…

Combinatorics · Mathematics 2017-03-16 Vladimir Blinovsky

The notion of thin sums matroids was invented to extend the notion of representability to non-finitary matroids. A matroid is tame if every circuit-cocircuit intersection is finite. We prove that a tame matroid is a thin sums matroid over a…

Combinatorics · Mathematics 2012-12-18 Nathan Bowler , Johannes Carmesin

This paper investigates infinite matroids from a categorical perspective. We prove that the category of infinite matroids is a proto-exact category in the sense of Dyckerhoff and Kapranov, thereby generalizing our previous result on the…

Combinatorics · Mathematics 2021-09-01 Chris Eppolito , Jaiung Jun

We prove that every 2k-edge-connected graph with countably many edge-ends admits a k-arc-connected orientation, extending the previous result by Assem, Koloschin and Pitz that also assumed the hypothesis of the graph being locally finite.…

Combinatorics · Mathematics 2025-10-09 Leandro Aurichi , Paulo Magalhães Júnior , Guilherme Eduardo Pinto

In this paper we highlight some enumerative results concerning matroids of low rank and prove the tail-ends of various sequences involving the number of matroids on a finite set to be log-convex. We give a recursion for a new, slightly…

Combinatorics · Mathematics 2007-05-23 W. M. B. Dukes

A super-minimally $k$-connected matroid is a $k$-connected matroid having no proper $k$-connected restriction of size at least $2k-2$. This extends the corresponding concept for graphs. For $k=2$ and $k=3$, we determine the maximum size of…

Combinatorics · Mathematics 2026-03-13 Wayne Ge , James Oxley

In this paper, we present an alternative proof of a finiteness theorem due to Bombieri, Masser and Zannier concerning intersections of a curve in the multiplicative group of dimension n with algebraic subgroups of dimension n-2. The proof…

Number Theory · Mathematics 2017-05-17 Laura Capuano , David Masser , Jonathan Pila , Umberto Zannier

We prove Ahlswede- Khachatrian conjecture. From this conjecture follows of several other conjectures including Manickam-Mikl\'{o}s-Singhi conjecture.

Combinatorics · Mathematics 2014-11-24 Vladimir Blinovsky

B\'ar\'any, Kalai, and Meshulam recently obtained a topological Tverberg-type theorem for matroids, which guarantees multiple coincidences for continuous maps from a matroid complex to d-dimensional Euclidean space, if the matroid has…

Combinatorics · Mathematics 2017-05-11 Pavle V. M. Blagojević , Albert Haase , Günter M. Ziegler