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相关论文: Canonical Decompositions of 3-Connected Graphs

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The 3-Decomposition Conjecture states that every connected cubic graph can be decomposed into a spanning tree, a 2-regular subgraph and a matching. We show that this conjecture holds for the class of connected plane cubic graphs.

组合数学 · 数学 2017-10-31 Arthur Hoffmann-Ostenhof , Tomáš Kaiser , Kenta Ozeki

A $3$-connected graph $G$ is essentially $4$-connected if, for any $3$-cut $S\subseteq V(G)$ of $G$, at most one component of $G-S$ contains at least two vertices. We prove that every essentially $4$-connected maximal planar graph $G$ on…

组合数学 · 数学 2021-01-28 Igor Fabrici , Jochen Harant , Samuel Mohr , Jens M. Schmidt

A wheel is a graph formed by a chordless cycle and a vertex that has at least three neighbors in the cycle. We prove that every 3-connected graph that does not contain a wheel as a subgraph is in fact minimally 3-connected. We give a new…

组合数学 · 数学 2013-09-10 Pierre Aboulker , Frédéric Havet , Nicolas Trotignon

The famous Gallai's Conjecture states that any connected graph with n vertices has a path decomposition containing at most (n+1)/2 paths. In this note, we explore graphs generated from removing edges from complete graphs. We first provide…

组合数学 · 数学 2022-11-01 Hua Wang , Andrew Zhang

If a biconnected graph stays connected after the removal of an arbitrary vertex and an arbitrary edge, then it is called 2.5-connected. We prove that every biconnected graph has a canonical decomposition into 2.5-connected components. These…

组合数学 · 数学 2020-07-15 Irene Heinrich , Till Heller , Eva Schmidt , Manuel Streicher

We construct tree-decompositions of graphs that distinguish all their k-blocks and tangles of order k, for any fixed integer k. We describe a family of algorithms to construct such decompositions, seeking to maximize their diversity subject…

组合数学 · 数学 2014-04-25 Johannes Carmesin , Reinhard Diestel , Matthias Hamann , Fabian Hundertmark

A $3$-connected graph is minimally 3-connected if removal of any edge destroys 3-connectivity. We present an algorithm for constructing minimally 3-connected graphs based on the results in (Dawes, JCTB 40, 159-168, 1986) using two…

组合数学 · 数学 2021-01-08 J. P. Costalonga , R. J. Kingan , S. R. Kingan

We adapt the classical 3-decomposition of any 2-connected graph to the case of simple graphs (no loops or multiple edges). By analogy with the block-cutpoint tree of a connected graph, we deduce from this decomposition a bicolored tree…

组合数学 · 数学 2010-12-24 Andrei Gagarin , Gilbert Labelle , Pierre Leroux , Timothy Walsh

In matching theory, one of the most fundamental and classical branches of combinatorics, {\em canonical decompositions} of graphs are powerful and versatile tools that form the basis of this theory. However, the abilities of the known…

组合数学 · 数学 2017-08-04 Nanao Kita

This work re-examines a classical construction of a 2-connected (simple) graph where every intermediate graph is 2-connected before detailing an analogous construction for 3-connected graphs which requires a graph equivalence relation…

组合数学 · 数学 2015-12-01 Jonathan McLaughlin

An ISK4 in a graph G is an induced subgraph of G that is isomorphic to a subdivision of K4 (the complete graph on four vertices). A wheel is a graph that consists of a chordless cycle, together with a vertex that has at least three…

组合数学 · 数学 2016-02-09 Martin Milanič , Irena Penev , Nicolas Trotignon

This paper is a short introduction to the theory of tangles, both in graphs and general connectivity systems. An emphasis is put on the correspondence between tangles of order k and k-connected components. In particular, we prove that there…

离散数学 · 计算机科学 2016-02-16 Martin Grohe

We give a simple proof of Tutte's theorem stating that the cycle space of a 3--connected graph is generated by the set of non-separating circuits of the graph. Keywords: graph, cycle, circuit, cycle space, non-separating circuit, strong…

组合数学 · 数学 2007-05-23 Alexander Kelmans

The theory of voltage graphs has become a standard tool in the study graphs admitting a semiregular group of automorphisms. We introduce the notion of a cyclic generalised voltage graph to extend the scope of this theory to graphs admitting…

组合数学 · 数学 2020-03-12 Primoz Potocnik , Micael Toledo

We show that every 3-regular circle graph has at least two pairs of twin vertices; consequently no such graph is prime with respect to the split decomposition. We also deduce that up to isomorphism, K_4 and K_{3,3} are the only 3-connected,…

组合数学 · 数学 2016-07-13 Lorenzo Traldi

A multigraph is exactly k-edge-connected if there are exactly k edge-disjoint paths between any pair of vertices. We characterize the class of exactly 3-edge-connected graphs, giving a synthesis involving two operations by which every…

组合数学 · 数学 2009-05-08 Carl Kingsford , Guillaume Marçais

The cycles are the only $2$-connected graphs in which any two nonadjacent vertices form a vertex cut. We generalize this fact by proving that for every integer $k\ge 3$ there exists a unique graph $G$ satisfying the following conditions:…

组合数学 · 数学 2022-10-28 Yanan Hu , Xingzhi Zhan , Leilei Zhang

A graph on at least ${{k+1}}$ vertices is uniformly $k$-connected if each pair of its vertices is connected by $k$ and not more than $k$ independent paths. We reinvestigate a recent constructive characterization of uniformly $3$-connected…

组合数学 · 数学 2024-08-07 Frank Göring , Tobias Hofmann

An arc of a graph is an oriented edge and a 3-arc is a 4-tuple $(v,u,x,y)$ of vertices such that both $(v,u,x)$ and $(u,x,y)$ are paths of length two. The 3-arc graph of a graph $G$ is defined to have vertices the arcs of $G$ such that two…

组合数学 · 数学 2013-11-14 Guangjun Xu , Sanming Zhou

These lecture notes are on automorphism groups of Cayley graphs and their applications to optimal fault-tolerance of some interconnection networks. We first give an introduction to automorphisms of graphs and an introduction to Cayley…

组合数学 · 数学 2017-04-04 Ashwin Ganesan