4 papers
Digraphs of Large Girth and Dichromatic Number in Tournaments with Large Dichromatic Number
Pierre Charbit, Samuel Coulomb
In the 1960s, Erdős and Hajnal conjectured that every graph with sufficiently large chromatic number contains a subgraph of large girth (size of a smallest cycle) and large chromat…
Clique Number of Tournaments II
Guillaume Aubian, Samuel Coulomb
The directed clique number of a tournament is the minimum, over all orderings of the vertices of , of the clique number of the graph whose edges are the arcs that…
Acyclic Dichromatic Number of Tournaments: these are the Champions
Pierre Aboulker, Pierre Charbit, Samuel Coulomb +2
The acyclic dichromatic number of an oriented graph is the minimum size of a vertex-partition such that the digraphs induced by any single part are acyclic, and the oriented bipart…
On the Modular Chromatic Index of Random Hypergraphs
Gaia Carenini, Samuel Coulomb
Let be two integers. We consider the problem of partitioning the hyperedge set of an -uniform hypergraph into the minimum number of edge-disjoint subh…