{ "id": "1412.3882", "version": "v1", "published": "2014-12-12T04:03:45.000Z", "updated": "2014-12-12T04:03:45.000Z", "title": "All fractional (g,f)-factors in graphs", "authors": [ "Zhiren Sun", "Sizhong Zhou" ], "comment": "5 pages", "categories": [ "math.CO" ], "abstract": "Let $G$ be a graph, and $g,f:V(G)\\rightarrow N$ be two functions with $g(x)\\leq f(x)$ for each vertex $x$ in $G$. We say that $G$ has all fractional $(g,f)$-factors if $G$ includes a fractional $r$-factor for every $r:V(G)\\rightarrow N$ such that $g(x)\\leq r(x)\\leq f(x)$ for each vertex $x$ in $G$. Let $H$ be a subgraph of $G$. We say that $G$ admits all fractional $(g,f)$-factors including $H$ if for every $r:V(G)\\rightarrow N$ with $g(x)\\leq r(x)\\leq f(x)$ for each vertex $x$ in $G$, $G$ includes a fractional $r$-factor $F_h$ with $h(e)=1$ for any $e\\in E(H)$, then we say that $G$ admits all fractional $(g,f)$-factors including $H$, where $h:E(G)\\rightarrow [0,1]$ is the indicator function of $F_h$. In this paper, we obtain a characterization for the existence of all fractional $(g,f)$-factors including $H$ and pose a sufficient condition for a graph to have all fractional $(g,f)$-factors including $H$.", "revisions": [ { "version": "v1", "updated": "2014-12-12T04:03:45.000Z" } ], "analyses": { "subjects": [ "05C70" ], "keywords": [ "fractional", "sufficient condition", "indicator function", "characterization" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1412.3882S" } } }