English

Correlation of paths between distinct vertices in a randomly oriented graph

Combinatorics 2013-03-20 v2

Abstract

We prove that in a random tournament the events {sa}\{s\rightarrow a\} and {tb}\{t\rightarrow b\} are positively correlated, for distinct vertices a,s,b,tKn.a,s,b,t \in K_n. It is also proven that the correlation between the events {sa}\{s\rightarrow a\} and {tb}\{t\rightarrow b\} in the random graphs G(n,p)G(n,p) and G(n,m)G(n,m) with random orientation is positive for every fixed p>0p>0 and sufficiently large nn (with m=p(n2)m=\left\lfloor p \binom{n}{2}\right\rfloor). We conjecture it to be positive for all pp and all nn. An exact recursion for ({sa}{tb})\P(\{s\rightarrow a\} \cap \{t\rightarrow b\}) in \gnp\gnp is given.

Keywords

Cite

@article{arxiv.1303.3961,
  title  = {Correlation of paths between distinct vertices in a randomly oriented graph},
  author = {Svante Linusson and Madeleine Leander},
  journal= {arXiv preprint arXiv:1303.3961},
  year   = {2013}
}

Comments

12 pages, 3 figures

R2 v1 2026-06-21T23:43:06.650Z