Journal Articles Journal of Graph Theory Year : 2017

Colouring graphs with constraints on connectivity

Abstract

A graph G has maximal local edge-connectivity k if the maximum number of edge-disjoint paths between every pair of distinct vertices x and y is at most k. We prove Brooks-type theorems for k-connected graphs with maximal local edge-connectivity k, and for any graph with maximal local edge-connectivity 3. We also consider several related graph classes defined by constraints on connectivity. In particular, we show that there is a polynomial-time algorithm that, given a 3-connected graph G with maximal local connectivity 3, outputs an optimal colouring for G. On the other hand, we prove, for k ≥ 3, that k-colourability is NP-complete when restricted to minimally k-connected graphs, and 3-colourability is NP-complete when restricted to (k − 1)-connected graphs with maximal local connectivity k. Finally, we consider a parameterization of k-colourability based on the number of vertices of degree at least k + 1, and prove that, even when k is part of the input, the corresponding parameterized problem is FPT.
Fichier principal
Vignette du fichier
colourConnectivity.pdf (393.68 Ko) Télécharger le fichier
Origin Files produced by the author(s)
Loading...

Dates and versions

hal-01570035 , version 1 (28-07-2017)

Identifiers

Cite

Pierre Aboulker, Nick Brettell, Frédéric Havet, Dániel Marx, Nicolas Trotignon. Colouring graphs with constraints on connectivity. Journal of Graph Theory, 2017, 85 (4), pp.814-838. ⟨10.1002/jgt.22109⟩. ⟨hal-01570035⟩
301 View
299 Download

Altmetric

Share

More