{ "id": "2004.14139", "version": "v1", "published": "2020-04-29T12:41:12.000Z", "updated": "2020-04-29T12:41:12.000Z", "title": "The size-Ramsey number of short subdivisions", "authors": [ "Nemanja Draganić", "Michael Krivelevich", "Rajko Nenadov" ], "comment": "12 pages, 1 figure", "categories": [ "math.CO" ], "abstract": "The $r$-size-Ramsey number $\\hat{R}_r(H)$ of a graph $H$ is the smallest number of edges a graph $G$ can have, such that for every edge-coloring of $G$ with $r$ colors there exists a monochromatic copy of $H$ in $G$. The notion of size-Ramsey numbers has been introduced by Erd\\H{o}s, Faudree, Rousseau and Schelp in 1978, and has attracted a lot of attention ever since. For a graph $H$, we denote by $H^q$ the graph obtained from $H$ by subdividing its edges with $q{-}1$ vertices each. In a recent paper of Kohayakawa, Retter and R{\\\"o}dl, it is shown that for all constant integers $q,r\\geq 2$ and every graph $H$ on $n$ vertices and of bounded maximum degree, the $r$-size-Ramsey number of $H^q$ is at most $(\\log n)^{20(q-1)}n^{1+1/q}$, for $n$ large enough. We improve upon this result using a significantly shorter argument by showing that $\\hat{R}_r(H^q)\\leq O(n^{1+1/q})$ for any such graph $H$.", "revisions": [ { "version": "v1", "updated": "2020-04-29T12:41:12.000Z" } ], "analyses": { "keywords": [ "size-ramsey number", "short subdivisions", "smallest number", "constant integers", "bounded maximum degree" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }