English

Quasi-4-Connected Components

Discrete Mathematics 2016-02-16 v1 Data Structures and Algorithms Combinatorics

Abstract

We introduce a new decomposition of a graphs into quasi-4-connected components, where we call a graph quasi-4-connected if it is 3-connected and it only has separations of order 3 that remove a single vertex. Moreover, we give a cubic time algorithm computing the decomposition of a given graph. Our decomposition into quasi-4-connected components refines the well-known decompositions of graphs into biconnected and triconnected components. We relate our decomposition to Robertson and Seymour's theory of tangles by establishing a correspondence between the quasi-4-connected components of a graph and its tangles of order 4.

Keywords

Cite

@article{arxiv.1602.04505,
  title  = {Quasi-4-Connected Components},
  author = {Martin Grohe},
  journal= {arXiv preprint arXiv:1602.04505},
  year   = {2016}
}
R2 v1 2026-06-22T12:50:00.749Z