7 papers
A Two-Player Zero Forcing Game
Dickson Y. B. Annor, Ben Howerton
We introduce a competitive two-player zero forcing game on a connected graph. Alice and Bob alternately seed white vertices or perform legal zero forces in their own colours, and e…
Induced Subgraph Bounds on the Zero Forcing Number and Chromatic Consequences
Dickson Y. B. Annor, Ben Howerton
Let be a graph with chromatic number , clique number and zero forcing number . We establish new lower bounds on in terms of induced triangle-free subg…
A Note on Inequalities for Three Domination Parameters
Dickson Y. B. Annor
In this short paper, we establish relations between the domination number , the total domination number , and the connected domination number of a graph. In partic…
Domination Parameters of Graph Covers
Dickson Y. B. Annor
A graph is a \emph{cover} of a graph if there exists an onto mapping , called a (\emph{covering}) \emph{projection}, such that maps the neighbours o…
Three Theorems on Negami's Planar Cover Conjecture
Dickson Annor, Yuri Nikolayevsky, Michael Payne
A long-standing Conjecture of S. Negami states that a connected graph has a finite planar cover if and only if it embeds in the projective plane. It is known that the Conjecture is…
has no -fold planar cover graph for
Dickson Y. B. Annor, Yuri Nikolayevsky, Michael S. Payne
S. Negami conjectured in that a connected graph has a finite planar cover if and only if it embeds in the projective plane. It follows from the works of D. Archdeacon, M. Fe…