37 citations · 142 across the 37 of their papers we have counts for
4 papers · 1 filter
Semi-Transitive Orientations and Word-Representable Graphs
Magnús M. Halldórsson, Sergey Kitaev, Artem Pyatkin
A graph is a \emph{word-representable graph} if there exists a word over the alphabet such that letters and alternate in if and only if f…
On representable graphs, semi-transitive orientations, and the representation numbers
Magnus Mar Halldorsson, Sergey Kitaev, Artem Pyatkin
A graph is representable if there exists a word over the alphabet such that letters and alternate in if and only if for each . I…
Vertex coloring acyclic digraphs and their corresponding hypergraphs
Geir Agnarsson, Agust Egilsson, Magnus Mar Halldorsson
We consider vertex coloring of an acyclic digraph $\Gdag$ in such a way that two vertices which have a common ancestor in $\Gdag$ receive distinct colors. Such colorings arise in a…
On Colorings of Squares of Outerplanar Graphs
Geir Agnarsson, Magnus Mar Halldorsson
We study vertex colorings of the square of an outerplanar graph . We find the optimal bound of the inductiveness, chromatic number and the clique number of as a func…