{ "id": "2105.11317", "version": "v1", "published": "2021-05-24T14:53:47.000Z", "updated": "2021-05-24T14:53:47.000Z", "title": "On $(t,r)$ broadcast domination of directed graphs", "authors": [ "Pamela E. Harris", "Peter Hollander", "Erik Insko" ], "comment": "18 pages, 18 figures", "categories": [ "math.CO" ], "abstract": "A dominating set of a graph $G$ is a set of vertices that contains at least one endpoint of every edge on the graph. The domination number of $G$ is the order of a minimum dominating set of $G$. The $(t,r)$ broadcast domination is a generalization of domination in which a set of broadcasting vertices emits signals of strength $t$ that decrease by 1 as they traverse each edge, and we require that every vertex in the graph receives a cumulative signal of at least $r$ from its set of broadcasting neighbors. In this paper, we extend the study of $(t,r)$ broadcast domination to directed graphs. Our main result explores the interval of values obtained by considering the directed $(t,r)$ broadcast domination numbers of all orientations of a graph $G$. In particular, we prove that in the cases $r=1$ and $(t,r) = (2,2)$, for every integer value in this interval, there exists an orientation $\\vec{G}$ of $G$ which has directed $(t,r)$ broadcast domination number equal to that value. We also investigate directed $(t,r)$ broadcast domination on the finite grid graph, the star graph, the infinite grid graph, and the infinite triangular lattice graph. We conclude with some directions for future study.", "revisions": [ { "version": "v1", "updated": "2021-05-24T14:53:47.000Z" } ], "analyses": { "subjects": [ "05C69", "05C12", "05C30", "68R05", "68R10" ], "keywords": [ "directed graphs", "broadcast domination number equal", "infinite triangular lattice graph", "infinite grid graph", "dominating set" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }