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Related papers: Quasi-4-Connected Components

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A connected graph is 4-connected if it contains at least five vertices and removing any three of them does not disconnect it. A frequent preprocessing step in graph drawing is to decompose a plane graph into its 4-connected components and…

Data Structures and Algorithms · Computer Science 2023-08-31 Sabine Cornelsen , Gregor Diatzko

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…

Combinatorics · Mathematics 2020-07-15 Irene Heinrich , Till Heller , Eva Schmidt , Manuel Streicher

We provide a unique decomposition of every 4-connected graph into parts that are either quasi-5-connected, cycles of triangle-torsos and 3-connected torsos on $\leq 5$ vertices, generalised double-wheels, or thickened $K_{4,m}$'s. The…

Combinatorics · Mathematics 2026-02-12 Jan Kurkofka , Tim Planken

We offer a new structural basis for the theory of 3-connected graphs, providing a unique decomposition of every such graph into parts that are either quasi 4-connected, wheels, or thickened $K_{3,m}$'s. Our construction is explicit,…

Combinatorics · Mathematics 2025-07-25 Johannes Carmesin , Jan Kurkofka

Tangles of graphs have been introduced by Robertson and Seymour in the context of their graph minor theory. Tangles may be viewed as describing "k-connected components" of a graph (though in a twisted way). They play an important role in…

Discrete Mathematics · Computer Science 2016-03-03 Martin Grohe , Pascal Schweitzer

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…

Combinatorics · Mathematics 2010-12-24 Andrei Gagarin , Gilbert Labelle , Pierre Leroux , Timothy Walsh

We introduce the standard decomposition, a way of decomposing a labeled graph into a sum of certain labeled subgraphs. We motivate this graph-theoretic concept by relating it to Connect Four decompositions of standard sets. We prove that…

Combinatorics · Mathematics 2013-04-08 Laurent Evain , Mathias Lederer , Bjarke Hammersholt Roune

We give a recursion formula to generate all equivalence classes of biconnected graphs with coefficients given by the inverses of the orders of their groups of automorphisms. We give a linear map to produce a connected graph with say, u,…

Combinatorics · Mathematics 2013-03-14 Angela Mestre

We present the first linear-time algorithm that computes the $4$-edge-connected components of an undirected graph. Hence, we also obtain the first linear-time algorithm for testing $4$-edge connectivity. Our results are based on a…

Data Structures and Algorithms · Computer Science 2021-05-10 Loukas Georgiadis , Giuseppe F. Italiano , Evangelos Kosinas

A constructive characterization of the class of uniformly $4$-connected graphs is presented. The characterization is based on the application of graph operations to appropriate vertex and edge sets in uniformly $4$-connected graphs, that…

Combinatorics · Mathematics 2025-07-11 Xiang Chen , Shuai Kou , Chengfu Qin , Liqiong Xu , Weihua Yang

Let $G=(V,E)$ be a connected graph. A subset $S\subset V$ is a cut of $G$ if $G-S$ is disconnected. A near triangulation is a 2-connected plane graph that has at most one face that is not a triangle. In this paper, we explore minimal cuts…

Combinatorics · Mathematics 2023-12-14 Brandon Du Preez

We describe the structure of triconnected graph with the help of its decomposition by 3-cutsets. We divide all 3-cutsets of a triconnected graph into rather small groups with a simple structure, named complexes. The detailed description of…

Combinatorics · Mathematics 2014-05-29 Dmitri Karpov , Alexey Pastor

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…

Discrete Mathematics · Computer Science 2016-02-16 Martin Grohe

We present an improved algorithm for computing the $4$-edge-connected components of an undirected graph in linear time. The new algorithm uses only elementary data structures, and it is simple to describe and to implement in the pointer…

Data Structures and Algorithms · Computer Science 2021-08-20 Loukas Georgiadis , Giuseppe F. Italiano , Evangelos Kosinas

In this work, we present the first linear time deterministic algorithm computing the 4-edge-connected components of an undirected graph. First, we show an algorithm listing all 3-edge-cuts in a given 3-edge-connected graph, and then we use…

Data Structures and Algorithms · Computer Science 2021-05-06 Wojciech Nadara , Mateusz Radecki , Marcin Smulewicz , Marek Sokołowski

We recall several known results about minimally 2-connected graphs, and show that they all follow from a decomposition theorem. Starting from an analogy with critically 2-connected graphs, we give structural characterizations of the classes…

Discrete Mathematics · Computer Science 2016-03-27 Pierre Aboulker , Marko Radovanović , Nicolas Trotignon , Kristina Vušković

For any class $\mathcal{C}$ of bipartite graphs, we define quasi-$\cal C$ to be the class of all graphs $G$ such that every bipartition of $G$ belongs to $\cal C$. This definition is motivated by a generalisation of the switch Markov chain…

Discrete Mathematics · Computer Science 2018-02-27 Martin Dyer , Haiko Müller

We present time-efficient distributed algorithms for decomposing graphs with large edge or vertex connectivity into multiple spanning or dominating trees, respectively. As their primary applications, these decompositions allow us to achieve…

Data Structures and Algorithms · Computer Science 2013-11-22 Keren Censor-Hillel , Mohsen Ghaffari , Fabian Kuhn

Let $G$ be a contraction critically quasi $5$-connected graph on at least $14$ vertices. If there is a vertex $x\in V_{4}(G)$ such that $G[N_{G}(x)]\cong K_{1,3}$ or $G[N_{G}(x)]\cong C_{4}$, then $G$ has a quasi $5$-contractible subgraph…

Combinatorics · Mathematics 2022-07-27 Shuai Kou , Chengfu Qin , Weihua Yang

In this paper, we show that the minimum number of vertices whose removal disconnects a connected strongly regular graph into non-singleton components, equals the size of the neighborhood of an edge for many graphs. These include blocks…

Combinatorics · Mathematics 2013-11-25 Sebastian M. Cioabă , Jack H. Koolen , Weiqiang Li
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