{ "id": "1903.05613", "version": "v1", "published": "2019-03-13T17:27:03.000Z", "updated": "2019-03-13T17:27:03.000Z", "title": "A lower bound for the radio number of graphs", "authors": [ "Devsi Bantva" ], "comment": "13 pages, CALDAM 2019 conference proceeding paper", "journal": "In: Pal S., Vijayakumar A. (eds) Algorithms and Discrete Applied Mathematics. CALDAM 2019. Lecture Notes in Computer Science, vol 11394, pp 161-173. Springer, Cham", "doi": "10.1007/978-3-030-11509-8_14", "categories": [ "math.CO" ], "abstract": "A radio labeling of a graph $G$ is a mapping $\\vp : V(G) \\rightarrow \\{0, 1, 2,...\\}$ such that $|\\vp(u)-\\vp(v)|\\geq \\diam(G) + 1 - d(u,v)$ for every pair of distinct vertices $u,v$ of $G$, where $\\diam(G)$ and $d(u,v)$ are the diameter of $G$ and distance between $u$ and $v$ in $G$, respectively. The radio number $\\rn(G)$ of $G$ is the smallest number $k$ such that $G$ has radio labeling with $\\max\\{\\vp(v):v \\in V(G)\\}$ = $k$. In this paper, we slightly improve the lower bound for the radio number of graphs given by Das \\emph{et al.} in [5] and, give necessary and sufficient condition to achieve the lower bound. Using this result, we determine the radio number for cartesian product of paths $P_{n}$ and the Peterson graph $P$. We give a short proof for the radio number of cartesian product of paths $P_{n}$ and complete graphs $K_{m}$ given by Kim \\emph{et al.} in [6].", "revisions": [ { "version": "v1", "updated": "2019-03-13T17:27:03.000Z" } ], "analyses": { "subjects": [ "05C78", "05C15", "05C12" ], "keywords": [ "radio number", "lower bound", "cartesian product", "distinct vertices", "radio labeling" ], "tags": [ "conference paper", "journal article" ], "publication": { "publisher": "Springer" }, "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }