{ "id": "2308.13874", "version": "v1", "published": "2023-08-26T13:17:25.000Z", "updated": "2023-08-26T13:17:25.000Z", "title": "Sufficient conditions for $k$-factors and spanning trees of graphs", "authors": [ "Guoyan Ao", "Ruifang Liu", "Jinjiang Yuan", "C. T. Ng", "T. C. E. Cheng" ], "comment": "17 pages, 3 figures", "categories": [ "math.CO" ], "abstract": "For any integer $k\\geq1,$ a graph $G$ has a $k$-factor if it contains a $k$-regular spanning subgraph. In this paper we prove a sufficient condition in terms of the number of $r$-cliques to guarantee the existence of a $k$-factor in a graph with minimum degree at least $\\delta$, which improves the sufficient condition of O \\cite{O2021} based on the number of edges. For any integer $k\\geq2,$ a spanning $k$-tree of a connected graph $G$ is a spanning tree in which every vertex has degree at most $k$. Motivated by the technique of Li and Ning \\cite{Li2016}, we present a tight spectral condition for an $m$-connected graph to have a spanning $k$-tree, which extends the result of Fan, Goryainov, Huang and Lin \\cite{Fan2021} from $m=1$ to general $m$. Let $T$ be a spanning tree of a connected graph. The leaf degree of $T$ is the maximum number of leaves adjacent to $v$ in $T$ for any $v\\in V(T)$. We provide a tight spectral condition for the existence of a spanning tree with leaf degree at most $k$ in a connected graph with minimum degree $\\delta$, where $k\\geq1$ is an integer.", "revisions": [ { "version": "v1", "updated": "2023-08-26T13:17:25.000Z" } ], "analyses": { "subjects": [ "05C50", "05C35" ], "keywords": [ "spanning tree", "sufficient condition", "connected graph", "tight spectral condition", "minimum degree" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }