{ "id": "1410.5750", "version": "v1", "published": "2014-10-21T17:31:38.000Z", "updated": "2014-10-21T17:31:38.000Z", "title": "Edge-decompositions of graphs with high minimum degree", "authors": [ "Ben Barber", "Daniela Kühn", "Allan Lo", "Deryk Osthus" ], "comment": "38 pages", "categories": [ "math.CO" ], "abstract": "A fundamental theorem of Wilson states that, for every graph $F$, every sufficiently large $F$-divisible clique has an $F$-decomposition. Here a graph $G$ is $F$-divisible if $e(F)$ divides $e(G)$ and the greatest common divisor of the degrees of $F$ divides the greatest common divisor of the degrees of $G$, and $G$ has an $F$-decomposition if the edges of $G$ can be covered by edge-disjoint copies of $F$. We extend this result to graphs which are allowed to be far from complete: our results imply that every sufficiently large $F$-divisible graph $G$ on $n$ vertices with minimum degree at least $(1- ( 9 |F|^{10})^{-1} +\\epsilon)n$ has an $F$-decomposition. Moreover, every sufficiently large $K_3$-divisible graph of minimum degree $0.956n$ has a $K_3$-decomposition. Our result significantly improves previous results towards the long-standing conjecture of Nash-Williams that every sufficiently large $K_3$-divisible graph with minimum degree $3n/4$ has a $K_3$-decomposition. For certain graphs, we can strengthen the general bound above. In particular, we obtain the asymptotically correct threshold of $n/2+o(n)$ for even cycles of length at least 6. Our main contribution is a general method which turns an approximate decomposition into an exact one.", "revisions": [ { "version": "v1", "updated": "2014-10-21T17:31:38.000Z" } ], "analyses": { "subjects": [ "05C70" ], "keywords": [ "high minimum degree", "sufficiently large", "greatest common divisor", "divisible graph", "edge-decompositions" ], "note": { "typesetting": "TeX", "pages": 38, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1410.5750B" } } }