English

Directed domination in oriented hypergraphs

Combinatorics 2019-04-05 v1

Abstract

Erd\H{o}s [On Sch\"utte problem, Math. Gaz. 47 (1963)] proved that every tournament on nn vertices has a directed dominating set of at most log(n+1)\log (n+1) vertices, where log\log is the logarithm to base 22. He also showed that there is a tournament on nn vertices with no directed domination set of cardinality less than logn2loglogn+1\log n - 2 \log \log n + 1. This notion of directed domination number has been generalized to arbitrary graphs by Caro and Henning in [Directed domination in oriented graphs, Discrete Appl. Math. (2012) 160:7--8.]. However, the generalization to directed r-uniform hypergraphs seems to be rare. Among several results, we prove the following upper and lower bounds on Γr1(H(n,r))\overrightarrow{\Gamma}_{r-1}(H(n,r)), the upper directed (r1)(r-1)-domination number of the complete rr-uniform hypergraph on nn vertices H(n,r)H(n,r), which is the main theorem of this paper: c(lnn)1r1Γr1(H(n,r))Clnn,c (\ln n)^{\frac{1}{r-1}} \le \overrightarrow{\Gamma}_{r-1}(H(n,r)) \le C \ln n, where rr is a positive integer and c=c(r)>0c= c(r) > 0 and C=C(r)>0C = C(r) > 0 are constants depending on rr.

Keywords

Cite

@article{arxiv.1904.02351,
  title  = {Directed domination in oriented hypergraphs},
  author = {Yair Caro and Adriana Hansberg},
  journal= {arXiv preprint arXiv:1904.02351},
  year   = {2019}
}