Directed graphs with lower orientation Ramsey thresholds
Combinatorics
2024-06-18 v2
Abstract
We investigate the threshold for the Ramsey-type property , where is the binomial random graph and indicates that every orientation of the graph contains the oriented graph as a subdigraph. Similarly to the classical Ramsey setting, the upper bound is known to hold for some constant , where denotes the maximum -density of the underlying graph of . While this upper bound is indeed the threshold for some , this is not always the case. We obtain examples arising from rooted products of orientations of sparse graphs (such as forests, cycles and, more generally, subcubic -free graphs) and arbitrarily rooted transitive triangles.
Keywords
Cite
@article{arxiv.2211.07033,
title = {Directed graphs with lower orientation Ramsey thresholds},
author = {Gabriel Ferreira Barros and Bruno Pasqualotto Cavalar and Yoshiharu Kohayakawa and Guilherme Oliveira Mota and Tássio Naia},
journal= {arXiv preprint arXiv:2211.07033},
year = {2024}
}
Comments
12 pages, 1 figure. To appear in RAIRO-Operations Research