English

Ramsey numbers of ordered graphs under graph operations

Combinatorics 2019-02-26 v2

Abstract

An ordered graph G\mathcal{G} is a simple graph together with a total ordering on its vertices. The (2-color) Ramsey number of G\mathcal{G} is the smallest integer NN such that every 2-coloring of the edges of the complete ordered graph on NN vertices has a monochromatic copy of G\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 nn vertices whose Ramsey number is nq+o(1)n^{q+o(1)} for any given exponent q(1,2)q\in(1,2).

Keywords

Cite

@article{arxiv.1902.00259,
  title  = {Ramsey numbers of ordered graphs under graph operations},
  author = {Jesse Geneson and Amber Holmes and Xujun Liu and Dana Neidinger and Yanitsa Pehova and Isaac Wass},
  journal= {arXiv preprint arXiv:1902.00259},
  year   = {2019}
}
R2 v1 2026-06-23T07:29:12.287Z