{ "id": "1905.04657", "version": "v1", "published": "2019-05-12T06:39:06.000Z", "updated": "2019-05-12T06:39:06.000Z", "title": "Long monochromatic paths and cycles in 2-edge-colored multipartite graphs", "authors": [ "József Balogh", "Alexandr Kostochka", "Mikhail Lavrov", "Xujun Liu" ], "comment": "46 pages, 4 figures", "categories": [ "math.CO" ], "abstract": "We solve four similar problems: For every fixed $s$ and large $n$, we describe all values of $n_1,\\ldots,n_s$ such that for every $2$-edge-coloring of the complete $s$-partite graph $K_{n_1,\\ldots,n_s}$ there exists a monochromatic (i) cycle $C_{2n}$ with $2n$ vertices, (ii) cycle $C_{\\geq 2n}$ with at least $2n$ vertices, (iii) path $P_{2n}$ with $2n$ vertices, and (iv) path $P_{2n+1}$ with $2n+1$ vertices. This implies a generalization for large $n$ of the conjecture by Gy\\'arf\\'as, Ruszink\\'o, S\\'ark\\H{o}zy and Szemer\\'edi that for every $2$-edge-coloring of the complete $3$-partite graph $K_{n,n,n}$ there is a monochromatic path $P_{2n+1}$. An important tool is our recent stability theorem on monochromatic connected matchings.", "revisions": [ { "version": "v1", "updated": "2019-05-12T06:39:06.000Z" } ], "analyses": { "subjects": [ "05C15", "05C35", "05C38" ], "keywords": [ "long monochromatic paths", "multipartite graphs", "similar problems", "important tool", "stability theorem" ], "note": { "typesetting": "TeX", "pages": 46, "language": "en", "license": "arXiv", "status": "editable" } } }