English

Counting restricted orientations of random graphs

Combinatorics 2020-01-01 v2

Abstract

We count orientations of G(n,p)G(n,p) avoiding certain classes of oriented graphs. In particular, we study Tr(n,p)T_r(n,p), the number of orientations of the binomial random graph G(n,p)G(n,p) in which every copy of KrK_r is transitive, and Sr(n,p)S_r(n,p), the number of orientations of G(n,p)G(n,p) containing no strongly connected copy of KrK_r. We give the correct order of growth of logTr(n,p)\log T_r(n,p) and logSr(n,p)\log S_r(n,p) up to polylogarithmic factors; for orientations with no cyclic triangle, this significantly improves a result of Allen, Kohayakawa, Mota and Parente. We also discuss the problem for a single forbidden oriented graph, and state a number of open problems and conjectures.

Keywords

Cite

@article{arxiv.1811.03080,
  title  = {Counting restricted orientations of random graphs},
  author = {Maurício Collares and Yoshiharu Kohayakawa and Robert Morris and Guilherme Oliveira Mota},
  journal= {arXiv preprint arXiv:1811.03080},
  year   = {2020}
}

Comments

16 pages + Appendix, 1 figure; minor changes

R2 v1 2026-06-23T05:08:09.358Z