{ "id": "1902.00259", "version": "v1", "published": "2019-02-01T10:12:11.000Z", "updated": "2019-02-01T10:12:11.000Z", "title": "Ramsey numbers of ordered graphs under graph operations", "authors": [ "Jesse Geneson", "Amber Holmes", "Xujun Liu", "Dana Neidinger", "Yanitsa Pehova", "Isaac Wass" ], "categories": [ "math.CO" ], "abstract": "An ordered graph $\\mathcal{G}$ is a simple graph together with a total ordering on its vertices. The (2-color) Ramsey number of $\\mathcal{G}$ is the smallest integer $N$ such that every 2-coloring of the edges of the complete ordered graph on $N$ vertices has a monochromatic copy of $\\mathcal{G}$ that respects the ordering. In this paper we investigate the effect of various graph operations on the Ramsey number of a given ordered graph, and detail a general framework for applying results on extremal functions of 0-1 matrices to ordered Ramsey problems. We apply this method to give upper bounds on the Ramsey number of ordered matchings arising from sum-decomposable permutations, an alternating ordering of the cycle, and an alternating ordering of the tight hyperpath. We also construct ordered matchings on $n$ vertices whose Ramsey number is $n^{q+o(1)}$ for any given exponent $q\\in(1,2)$.", "revisions": [ { "version": "v1", "updated": "2019-02-01T10:12:11.000Z" } ], "analyses": { "subjects": [ "05D10" ], "keywords": [ "ramsey number", "graph operations", "smallest integer", "complete ordered graph", "construct ordered matchings" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }