{ "id": "1503.03272", "version": "v1", "published": "2015-03-11T11:10:24.000Z", "updated": "2015-03-11T11:10:24.000Z", "title": "On the existence of vertex-disjoint subgraphs with high degree sums", "authors": [ "Shuya Chiba", "Nicolas Lichiardopol" ], "comment": "25 pages", "categories": [ "math.CO" ], "abstract": "For a graph $G$, we denote by $\\sigma_{2}(G)$ the minimum degree sum of two non-adjacent vertices if $G$ is non-complete; otherwise, $\\sigma_{2}(G) = +\\infty$. In this paper, we prove the following two results; (i) If $s_{1}$ and $s_{2}$ are integers with $s_{1}, s_{2} \\ge 2$ and if $G$ is a non-complete graph with $\\sigma_{2}(G) \\ge 2(s_{1} + s_{2} + 1) - 1$, then $G$ contains two vertex-disjoint subgraphs $H_{1}$ and $H_{2}$ such that each $H_{i}$ is a graph of order at least $s_{i}+1$ with $\\sigma_{2}(H_{i}) \\ge 2s_{i} - 1$. (ii) If $s_{1}$ and $s_{2}$ are integers with $s_{1}, s_{2} \\ge 2$ and if $G$ is a non-complete triangle-free graph with $\\sigma_{2}(G) \\ge 2(s_{1} + s_{2}) - 1$, then $G$ contains two vertex-disjoint subgraphs $H_{1}$ and $H_{2}$ such that each $H_{i}$ is a graph of order at least $2s_{i}$ with $\\sigma_{2}(H_{i}) \\ge 2s_{i} - 1$. By using this kind of results, we also give some corollaries concerning the degree conditions for vertex-disjoint cycles.", "revisions": [ { "version": "v1", "updated": "2015-03-11T11:10:24.000Z" } ], "analyses": { "keywords": [ "high degree sums", "vertex-disjoint subgraphs", "non-complete triangle-free graph", "minimum degree sum", "non-complete graph" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150303272C" } } }