{ "id": "2408.11644", "version": "v1", "published": "2024-08-21T14:16:17.000Z", "updated": "2024-08-21T14:16:17.000Z", "title": "The saturation number for unions of four cliques", "authors": [ "Ruo-Xuan Li", "Rong-Xia Hao", "Zhen He", "Wen-Han Zhu" ], "comment": "17pages", "categories": [ "math.CO" ], "abstract": "A graph $G$ is $H$-saturated if $H$ is not a subgraph of $G$ but $H$ is a subgraph of $G + e$ for any edge $e$ in $\\overline{G}$. The saturation number $sat(n,H)$ for a graph $H$ is the minimal number of edges in any $H$-saturated graph of order $n$. The $sat(n, K_{p_1} \\cup K_{p_2} \\cup K_{p_3})$ with $p_3 \\ge p_1 + p_2$ was given in [Discrete Math. 347 (2024) 113868]. In this paper, $sat(n,K_{p_1} \\cup K_{p_2} \\cup K_{p_3} \\cup K_{p_4})$ with $p_{i+1} - p_i \\ge p_1$ for $2 \\le i\\le 3$ and $4\\le p_1\\le p_2$ is determined.", "revisions": [ { "version": "v1", "updated": "2024-08-21T14:16:17.000Z" } ], "analyses": { "subjects": [ "05C35" ], "keywords": [ "saturation number", "minimal number", "discrete math", "saturated graph" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }