Deploying robots with two sensors in -free graphs
arXiv:1308.5450 · doi:10.1002/jgt.21898
Abstract
Let be a graph of minimum degree at least two with no induced subgraph isomorphic to . We prove that if is not isomorphic to one of eight exceptional graphs, then it is possible to assign two-element subsets of to the vertices of in such a way that for every and every vertex the label is assigned to or one of its neighbors. It follows that has fractional domatic number at least . This is motivated by a problem in robotics and generalizes a result of Fujita, Yamashita and Kameda who proved that the same conclusion holds for all -regular graphs.