{ "id": "2304.00859", "version": "v1", "published": "2023-04-03T10:14:37.000Z", "updated": "2023-04-03T10:14:37.000Z", "title": "On the strength and domination number of graphs", "authors": [ "Yukio Takahashi", "Rikio Ichishima", "Francesc A. Muntaner-Batle" ], "categories": [ "math.CO" ], "abstract": "A numbering $f$ of a graph $G$ of order $n$ is a labeling that assigns distinct elements of the set $\\left\\{ 1,2,\\ldots ,n\\right\\} $ to the vertices of $G$. The strength $\\textrm{str}_{f}\\left( G\\right)$ of a numbering $f:V\\left( G\\right) \\rightarrow \\left\\{ 1,2,\\ldots ,n\\right\\} $ of $G$ is defined by% \\begin{equation*} \\mathrm{str}_{f}\\left( G\\right) =\\max \\left\\{ f\\left( u\\right) +f\\left( v\\right) \\left| uv\\in E\\left( G\\right) \\right. \\right\\} \\text{,} \\end{equation*}% that is, $\\mathrm{str}_{f}\\left( G\\right) $ is the maximum edge label of $G$ and the strength\\ \\textrm{str}$\\left( G\\right) $ of a graph $G$ itself is \\begin{equation*} \\mathrm{str}\\left( G\\right) =\\min \\left\\{ \\mathrm{str}_{f}\\left( G\\right) \\left| f\\text{ is a numbering of }G\\right. \\right\\} \\text{.} \\end{equation*} In this paper, we present a sharp lower bound for the strength of a graph in terms of its domination number as well as its (edge) covering and (edge) independence number. We also provide a necessary and sufficient condition for the strength of a graph to attain the earlier bound in terms of their subgraph structure. In addition, we establish a sharp lower bound for the domination number of a graph under certain conditions.", "revisions": [ { "version": "v1", "updated": "2023-04-03T10:14:37.000Z" } ], "analyses": { "subjects": [ "05C78", "90C27" ], "keywords": [ "domination number", "sharp lower bound", "maximum edge label", "assigns distinct elements", "independence number" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }