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We introduce a new width parameter for matroids called decomposition width and prove that every matroid property expressible in the monadic second order logic can be computed in linear time for matroids with bounded decomposition width if…

Discrete Mathematics · Computer Science 2009-04-21 Daniel Kral

Let $M$ be a 3-connected binary matroid and let $Y(M)$ be the set of elements of $M$ avoiding at least $r(M)+1$ non-separating cocircuits of $M$. Lemos proved that $M$ is non-graphic if and only if $Y(M)\neq\emp$. We generalize this result…

Combinatorics · Mathematics 2012-11-27 João Paulo Costalonga

We show that all the tangles in a finite graph or matroid can be distinguished by a single tree-decomposition that is invariant under the automorphisms of the graph or matroid. This comes as a corollary of a similar decomposition theorem…

Combinatorics · Mathematics 2017-04-19 Reinhard Diestel , Fabian Hundertmark , Sahar Lemanczyk

We introduce delta-graphic matroids, which are matroids whose bases form graphic delta-matroids. The class of delta-graphic matroids contains graphic matroids as well as cographic matroids and is a proper subclass of the class of regular…

Combinatorics · Mathematics 2022-10-05 Duksang Lee , Sang-il Oum

We show that there exist $k$-colorable matroids that are not $(b,c)$-decomposable when $b$ and $c$ are constants. A matroid is $(b,c)$-decomposable, if its ground set of elements can be partitioned into sets $X_1, X_2, \ldots, X_l$ with the…

Data Structures and Algorithms · Computer Science 2022-06-30 Marilena Leichter , Benjamin Moseley , Kirk Pruhs

We prove that a large family of graphs which are decomposable with respect to the modular decomposition can be reconstructed from their collection of vertex-deleted subgraphs.

Combinatorics · Mathematics 2012-02-28 Robert Brignall , Nicholas Georgiou , Robert J. Waters

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

It has recently been shown that infinite matroids can be axiomatized in a way that is very similar to finite matroids and permits duality. This was previously thought impossible, since finitary infinite matroids must have non-finitary…

Combinatorics · Mathematics 2012-07-12 Henning Bruhn , Reinhard Diestel

We introduce and study filtrations of a matroid on a linearly ordered ground set, which are particular sequences of nested sets. A given basis can be decomposed into a uniquely defined sequence of bases of minors, such that these bases have…

Combinatorics · Mathematics 2018-07-19 Emeric Gioan , Michel Las Vergnas

We specify what is meant for a polytope to be reconstructible from its graph or dual graph. And we introduce the problem of class reconstructibility, i.e., the face lattice of the polytope can be determined from the (dual) graph within a…

Combinatorics · Mathematics 2022-08-05 Guillermo Pineda-Villavicencio , Benjamin Schröter

Multimatroids generalize matroids, delta-matroids, and isotropic systems, and transition polynomials of multimatroids subsume various polynomials for these latter combinatorial structures, such as the interlace polynomial and the…

Combinatorics · Mathematics 2017-08-18 Robert Brijder

A mixed graph is a graph with some directed edges and some undirected edges. We introduce the notion of mixed matroids as a generalization of mixed graphs. A mixed matroid can be viewed as an oriented matroid in which the signs over a fixed…

Combinatorics · Mathematics 2007-05-23 J. Orestes Cerdeira , Raul Cordovil

Zaslavsky introduced the concept of lifted-graphic matroid. For binary matroids, a binary elementary lift can be defined in terms of the splitting operation. In this paper, we give a method to get a forbidden-minor characterization for the…

Combinatorics · Mathematics 2019-10-15 Ganesh Mundhe , Y. M. Borse , K. V. Dalvi

We consider the class of graphs for which the edge connectivity is equal to the maximum number of edge-disjoint spanning trees, and the natural generalization to matroids, where the cogirth is equal to the number of disjoint bases. We…

Combinatorics · Mathematics 2014-02-10 Robert F. Bailey , Mike Newman , Brett Stevens

Fleischner introduced the idea of splitting a vertex of degree at least three in a connected graph and used the operation to characterize Eulerian graphs. Raghunathan et. al. extended the splitting operation from graphs to binary matroids.…

Combinatorics · Mathematics 2018-09-28 S. B. Dhotre , P. P. Malavadkar

The class of cographs or complement-reducible graphs is the class of graphs that can be generated from $K_1$ using the operations of disjoint union and complementation. By analogy, this paper introduces the class of binary comatroids as the…

Combinatorics · Mathematics 2021-10-20 James Oxley , Jagdeep Singh

We establish the following splitter theorem for graphs and its generalization for matroids: Let $G$ and $H$ be $3$-connected simple graphs such that $G$ has an $H$-minor and $k:=|V(G)|-|V(H)|\ge 2$. Let $n:=\left\lceil k/2\right\rceil+1$.…

Combinatorics · Mathematics 2017-12-13 João Paulo Costalonga

We begin with a review of Tutte's homotopy theory, which concerns the structure of certain graph associated to a matroid (together with some extra data). Concretely, Tutte's path theorem asserts that this graph is connected, and his…

Combinatorics · Mathematics 2026-01-21 Matthew Baker , Tong Jin , Oliver Lorscheid

We provide a combinatorial study of split matroids, a class that was motivated by the study of matroid polytopes from a tropical geometry point of view. A nice feature of split matroids is that they generalize paving matroids, while being…

Combinatorics · Mathematics 2022-02-10 Kristóf Bérczi , Tamás Király , Tamás Schwarcz , Yutaro Yamaguchi , Yu Yokoi

An infinite matroid is graphic if all of its finite minors are graphic and the intersection of any circuit with any cocircuit is finite. We show that a matroid is graphic if and only if it can be represented by a graph-like topological…

Combinatorics · Mathematics 2013-09-17 Nathan Bowler , Johannes Carmesin , Robin Christian