{ "id": "2106.08975", "version": "v1", "published": "2021-06-16T17:16:49.000Z", "updated": "2021-06-16T17:16:49.000Z", "title": "Short proofs for long induced paths", "authors": [ "Nemanja Draganić", "Stefan Glock", "Michael Krivelevich" ], "comment": "9 pages", "categories": [ "math.CO" ], "abstract": "We present a modification of the DFS graph search algorithm, suited for finding long induced paths. We use it to give simple proofs of the following results. We show that the induced size-Ramsey number of paths satisfies $\\hat{R}_{\\mathrm{ind}}(P_n)\\leq 5\\cdot 10^7n$, thus giving an explicit constant in the linear bound, improving the previous bound with a large constant from a regularity lemma argument by Haxell, Kohayakawa and {\\L}uczak. We also provide a bound for the $k$-color version, showing that $\\hat{R}_{\\mathrm{ind}}^k(P_n)=O(k^3\\log^4k)n$. Finally, we present a new short proof of the fact that the binomial random graph in the supercritical regime, $G(n,\\frac{1+\\varepsilon}{n})$, contains typically an induced path of length $\\Theta(\\varepsilon^2) n$.", "revisions": [ { "version": "v1", "updated": "2021-06-16T17:16:49.000Z" } ], "analyses": { "keywords": [ "short proof", "dfs graph search algorithm", "regularity lemma argument", "binomial random graph", "paths satisfies" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable" } } }