{ "id": "2203.06594", "version": "v1", "published": "2022-03-13T07:53:26.000Z", "updated": "2022-03-13T07:53:26.000Z", "title": "On join product and local antimagic chromatic number of regular graphs", "authors": [ "Gee-Choon Lau", "Wai-Chee Shiu" ], "categories": [ "math.CO" ], "abstract": "Let $G = (V,E)$ be a connected simple graph of order $p$ and size $q$. A graph $G$ is called local antimagic if $G$ admits a local antimagic labeling. A bijection $f : E \\to \\{1,2,\\ldots,q\\}$ is called a local antimagic labeling of $G$ if for any two adjacent vertices $u$ and $v$, we have $f^+(u) \\ne f^+(v)$, where $f^+(u) = \\sum_{e\\in E(u)} f(e)$, and $E(u)$ is the set of edges incident to $u$. Thus, any local antimagic labeling induces a proper vertex coloring of $G$ if vertex $v$ is assigned the color $f^+(v)$. The local antimagic chromatic number, denoted $\\chi_{la}(G)$, is the minimum number of induced colors taken over local antimagic labeling of $G$. Let $G$ and $H$ be two vertex disjoint graphs. The join graph of $G$ and $H$, denoted $G \\vee H$, is the graph $V(G\\vee H) = V(G) \\cup V(H)$ and $E(G\\vee H) = E(G) \\cup E(H) \\cup \\{uv \\,|\\, u\\in V(G), v \\in V(H)\\}$. In this paper, we show the existence of non-complete regular graphs with arbitrarily large order, regularity and local antimagic chromatic numbers.", "revisions": [ { "version": "v1", "updated": "2022-03-13T07:53:26.000Z" } ], "analyses": { "subjects": [ "05C78", "05C69" ], "keywords": [ "local antimagic chromatic number", "join product", "local antimagic labeling induces", "vertex disjoint graphs", "non-complete regular graphs" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }