8 citations · 20 across the 17 of their papers we have counts for
5 papers · 1 filter
Homomorphically Full Oriented Graphs
Thomas Bellitto, Christopher Duffy, Gary MacGillivray
Homomorphically full graphs are those for which every homomorphic image is isomorphic to a subgraph. We extend the definition of homomorphically full to oriented graphs in two diff…
Switching -edge-coloured graphs using non-Abelian groups
Chris Duffy, Gary MacGillivray, Ben Tremblay
Let be a graph whose edges are each assigned one of the -colours , and let be a subgroup of . The operation of switching at a vertex with respe…
Complexity of injective homomorphisms to small tournaments, and of injective oriented colourings
Russell J. Campbell, Nancy E. Clarke, Gary MacGillivray
Several possible definitions of local injectivity for a homomorphism of an oriented graph to an oriented graph are considered. In each case, we determine the complexity of…
Obstructions to some injective oriented colourings
Russell Campbell, Nancy E. Clarke, Gary MacGillivray
Each of several possible definitions of local injectivity for a homomorphism of an oriented graph to an oriented graph leads to an injective oriented colouring problem. For…
The 2-colouring problem for -mixed graphs with switching is polynomial
Richard C Brewster, Arnott Kidner, Gary MacGillivray
A mixed graph is a set of vertices together with an edge set and an arc set. An -mixed graph is a mixed graph whose edges are each assigned one of colours, and whose…