English

Vizing's conjecture for cographs

Combinatorics 2016-10-04 v3

Abstract

We show that if GG is a cograph, that is P4P_4-free, then for any graph HH, γ(GH)γ(G)γ(H)\gamma(G\square H)\geq \gamma(G)\gamma(H). By the characterization of cographs as a finite sequence of unions and joins of K1K_1, this result easily follows from that of Bartsalkin and German. However, the techniques used are new and may be useful to prove other results.

Keywords

Cite

@article{arxiv.1609.08370,
  title  = {Vizing's conjecture for cographs},
  author = {Elliot Krop},
  journal= {arXiv preprint arXiv:1609.08370},
  year   = {2016}
}

Comments

6 pages, 2 figures. Since cographs are disjoint unions of graphs with domination numbers one or two, this result is implied by the work of Bartsalkin and German. However, the techniques presented are new and may be useful to other researchers in the field

R2 v1 2026-06-22T16:02:38.316Z