5 papers
3-Colouring Graphs Excluding a Fixed Minor
Vida Dujmović, Hussein Houdrouge, Pat Morin
We show that, for every fixed graph , every -vertex graph that excludes as a minor is -colourable with clustering . That is, there exists a function…
2-dimensional unit vector flows
Hussein Houdrouge, Bobby Miraftab, Pat Morin
We study -dimensional unit vector flows on graphs, that is, nowhere-zero flows that assign to each oriented edge a unit vector in . We give a new geometric charac…
Separation Number and Treewidth, Revisited
Hussein Houdrouge, Babak Miraftab, Pat Morin
We give a constructive proof of the fact that the treewidth of a graph is bounded by a linear function of the separation number of .
Connected Dominating Sets in Triangulations
Prosenjit Bose, Vida Dujmović, Hussein Houdrouge +2
We show that every -vertex triangulation has a connected dominating set of size at most . Equivalently, every vertex triangulation has a spanning tree with at least…
Linear versus centred chromatic numbers
Prosenjit Bose, Vida Dujmović, Hussein Houdrouge +2
$\DeclareMathOperator{\chicen}{χ_{\mathrm{cen}}}\DeclareMathOperator{\chilin}{χ_{\mathrm{lin}}}$ A centred colouring of a graph is a vertex colouring in which every connected subgr…