{ "id": "2204.03630", "version": "v1", "published": "2022-04-07T17:52:20.000Z", "updated": "2022-04-07T17:52:20.000Z", "title": "Existence of $2$-Factors in Tough Graphs without Forbidden Subgraphs", "authors": [ "Elizabeth Grimm", "Songling Shan", "Anna Johnsen" ], "categories": [ "math.CO" ], "abstract": "For a given graph $R$, a graph $G$ is $R$-free if $G$ does not contain $R$ as an induced subgraph. It is known that every $2$-tough graph with at least three vertices has a $2$-factor. In graphs with restricted structures, it was shown that every $2K_2$-free $3/2$-tough graph with at least three vertices has a $2$-factor, and the toughness bound $3/2$ is best possible. In viewing $2K_2$, the disjoint union of two edges, as a linear forest, in this paper, for any linear forest $R$ on 5, 6, or 7 vertices, we find the sharp toughness bound $t$ such that every $t$-tough $R$-free graph on at least three vertices has a 2-factor.", "revisions": [ { "version": "v1", "updated": "2022-04-07T17:52:20.000Z" } ], "analyses": { "keywords": [ "tough graph", "forbidden subgraphs", "linear forest", "sharp toughness bound", "free graph" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }