Outputs (2)

Connectedness of the graph of vertex-colourings (2008)
Journal Article
Cereceda, L., van den Heuvel, J., & Johnson, M. (2008). Connectedness of the graph of vertex-colourings. Discrete Mathematics, 308(5-6), 913-919. https://doi.org/10.1016/j.disc.2007.07.028

For a positive integer k and a graph G, the k-colour graph of G , Ck(G), is the graph that has the proper k-vertex-colourings of G as its vertex set, and two k -colourings are joined by an edge in Ck(G) if they differ in colour on just one vertex of... Read More about Connectedness of the graph of vertex-colourings.

Transversals of subtree hypergraphs and the source location problem in digraphs (2008)
Journal Article
Heuvel van den, J., & Johnson, M. (2008). Transversals of subtree hypergraphs and the source location problem in digraphs. Networks, 51(2), 113-119. https://doi.org/10.1002/net.20206

A hypergraph H = (V,E) is a subtree hypergraph if there is a tree T on V such that each hyperedge of E induces a subtree of T. Since the number of edges of a subtree hypergraph can be exponential in n = |V|, one can not always expect to be able to fi... Read More about Transversals of subtree hypergraphs and the source location problem in digraphs.