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Related papers: Matroids, Delta-matroids and Embedded Graphs

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Building on prior work that established Matrix Quasi-tree Theorems for special embedded graphs, in this paper, we develop a comprehensive theory applicable to all embedded graphs. We introduce symbolic skew-adjacency matrices and reduction…

Combinatorics · Mathematics 2025-12-02 Qingying Deng , Xian'an Jin , Qi Yan , Yexiang Yan

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

The Tutte polynomial is a well-studied invariant of graphs and matroids. We first extend the Tutte polynomial from graphs to hypergraphs, and more generally from matroids to polymatroids, as a two-variable polynomial. Our definition is…

Combinatorics · Mathematics 2020-07-23 Olivier Bernardi , Tamas Kalman , Alex Postnikov

We present a concept called the branch-depth of a connectivity function, that generalizes the tree-depth of graphs. Then we prove two theorems showing that this concept aligns closely with the notions of tree-depth and shrub-depth of graphs…

Combinatorics · Mathematics 2020-11-05 Matt DeVos , O-joung Kwon , Sang-il Oum

In this short note we make a few remarks on a class of generalized incidence matrices whose matroids do not depend on the orientation of the underlying graph and natural commutative algebras associated to such matrices.

Combinatorics · Mathematics 2020-05-14 Boris Shapiro , Arkady Vaintrob

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

Starting from any finite simple graph, one can build a reflexive polytope known as a symmetric edge polytope. The first goal of this paper is to show that symmetric edge polytopes are intrinsically matroidal objects: more precisely, we…

Combinatorics · Mathematics 2023-07-12 Alessio D'Alì , Martina Juhnke-Kubitzke , Melissa Koch

We introduce the minor-closed, dual-closed class of multi-path matroids. We give a polynomial-time algorithm for computing the Tutte polynomial of a multi-path matroid, we describe their basis activities, and we prove some basic structural…

Combinatorics · Mathematics 2024-08-07 Joseph E. Bonin , Omer Gimenez

We provide a full classification of all families of matroids that are closed under duality and minors, and for which the Tutte polynomial is a universal valuative invariant. There are four inclusion-wise maximal families, two of which are…

Combinatorics · Mathematics 2025-02-10 Luis Ferroni , Benjamin Schröter

Recently, we introduced the twist polynomials of delta-matroids and gave a characterization of even normal binary delta-matroids whose twist polynomials have only one term and posed a problem: what would happen for odd binary…

Combinatorics · Mathematics 2022-05-10 Qi Yan , Xian'an Jin

Brylawski proved the coefficients of the Tutte polynomial of a matroid satisfy a set of linear relations. We extend these relations to a generalization of the Tutte polynomial that includes greedoids and antimatroids. This leads to families…

Combinatorics · Mathematics 2014-05-16 Gary Gordon

A G-gain graph is a graph whose oriented edges are labeled invertibly from a group G. Zaslavsky proposed two matroids of G-gain graphs, called frame matroids and lift matroids, and investigated linear representations of them. Each matroid…

Combinatorics · Mathematics 2012-11-12 Shin-ichi Tanigawa

We give two graph theoretical characterizations of tope graphs of (complexes of) oriented matroids. The first is in terms of excluded partial cube minors, the second is that all antipodal subgraphs are gated. A direct consequence is a third…

Combinatorics · Mathematics 2019-05-29 Kolja Knauer , Tilen Marc

A seminal result by Whitney describes when two graphs have the same cycles. We consider the analogous problem for even cycle matroids. A representation of an even cycle matroid is a pair formed by a graph together with a special set of…

Combinatorics · Mathematics 2011-09-15 Bertrand Guenin , Irene Pivotto , Paul Wollan

The handle slide operation, originally defined for ribbon graphs, was extended to delta-matroids by I. Moffatt and E. Mphako-Bandab, who show that, using a delta-matroid analogue of handle slides, every binary delta-matroid in which the…

Combinatorics · Mathematics 2022-03-10 Rémi Cocou Avohou , Brigitte Servatius , Herman Servatius

This paper surveys a comprehensive, although not exhaustive, sampling of graph polynomials with the goal of providing a brief overview of a variety of techniques defining a graph polynomial and then for decoding the combinatorial…

Combinatorics · Mathematics 2008-07-01 Joanna Ellis-Monaghan , Criel Merino

We generalize the tree-confluent graphs to a broader class of graphs called Delta-confluent graphs. This class of graphs and distance-hereditary graphs, a well-known class of graphs, coincide. Some results about the visualization of…

Computational Geometry · Computer Science 2007-05-23 David Eppstein , Michael T. Goodrich , Jeremy Yu Meng

A graph is chordal if every cycle of length at least four has a chord. In 1961, Dirac characterized chordal graphs as those graphs that can be built from complete graphs by repeated clique-sums. Generalizing this, we consider the class of…

Combinatorics · Mathematics 2024-05-03 James Dylan Douthitt , James Oxley

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

The Tutte polynomial is the most general invariant of matroids and graphs that can be computed recursively by deleting and contracting edges. We generalize this invariant to any class of combinatorial objects with deletion and contraction…

Combinatorics · Mathematics 2019-02-04 Clément Dupont , Alex Fink , Luca Moci