{ "id": "1405.6560", "version": "v1", "published": "2014-05-26T13:02:03.000Z", "updated": "2014-05-26T13:02:03.000Z", "title": "Sharp threshold for embedding combs and other spanning trees in random graphs", "authors": [ "Richard Montgomery" ], "comment": "20 pages", "categories": [ "math.CO" ], "abstract": "When $k|n$, the tree $\\mathrm{Comb}_{n,k}$ consists of a path containing $n/k$ vertices, each of whose vertices has a disjoint path length $k-1$ beginning at it. We show that, for any $k=k(n)$ and $\\epsilon>0$, the binomial random graph $\\mathcal{G}(n,(1+\\epsilon)\\log n/ n)$ almost surely contains $\\mathrm{Comb}_{n,k}$ as a subgraph. This improves a recent result of Kahn, Lubetzky and Wormald. We prove a similar statement for a more general class of trees containing both these combs and all bounded degree spanning trees which have at least $\\epsilon n/ \\log^9n$ disjoint bare paths length $\\lceil\\log^9 n\\rceil$. We also give an efficient method for finding large expander subgraphs in a binomial random graph. This allows us to improve a result on almost spanning trees by Balogh, Csaba, Pei and Samotij.", "revisions": [ { "version": "v1", "updated": "2014-05-26T13:02:03.000Z" } ], "analyses": { "subjects": [ "05C05", "05C80" ], "keywords": [ "spanning trees", "sharp threshold", "embedding combs", "binomial random graph", "disjoint bare paths length" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1405.6560M" } } }