English

A canonical Ramsey theorem with list constraints in random (hyper-)graphs

Combinatorics 2026-02-10 v3

Abstract

The celebrated canonical Ramsey theorem of Erd\H{o}s and Rado implies that for a given kk-uniform hypergraph (or kk-graph) HH, if nn is sufficiently large then any colouring of the edges of the complete kk-graph Kn(k)K^{(k)}_n gives rise to copies of HH that exhibit certain colour patterns. We are interested in sparse random versions of this result and the threshold at which the random kk-graph G(k)(n,p){\mathbf{G}}^{(k)}(n,p) inherits the canonical Ramsey properties of Kn(k)K^{(k)}_n. Our main result here pins down this threshold when we focus on colourings that are constrained by some prefixed lists. This result is applied in an accompanying work of the authors on the threshold for the canonical Ramsey property (with no list constraints) in the case that HH is a (2-uniform) even cycle.

Keywords

Cite

@article{arxiv.2304.01846,
  title  = {A canonical Ramsey theorem with list constraints in random (hyper-)graphs},
  author = {José D. Alvarado and Yoshiharu Kohayakawa and Patrick Morris and Guilherme O. Mota},
  journal= {arXiv preprint arXiv:2304.01846},
  year   = {2026}
}

Comments

18 pages, final version to appear in The Electronic Journal of Combinatorics (E-JC). An extended abstract introducing our result here (focusing just on the case of graphs) appeared in the proceedings of the XII Latin-American Algorithms, Graphs and Optimization Symposium (LAGOS 2023)

R2 v1 2026-06-28T09:49:05.743Z