An improved Moore bound for mixed graphs
Combinatorics
2018-04-26 v3
Abstract
A mixed graph can contain both (undirected) edges and arcs (directed edges). Here we derive an improved Moore-like bound for the maximum number of vertices of a mixed graph with diameter at least three. Moreover, a complete enumeration of all optimal -regular mixed graphs with diameter three is presented, so proving that, in general, the proposed bound cannot be improved.
Cite
@article{arxiv.1610.00116,
title = {An improved Moore bound for mixed graphs},
author = {C. Dalfó and M. A. Fiol and N. López},
journal= {arXiv preprint arXiv:1610.00116},
year = {2018}
}