English

On the 3-$\gamma_t$-Critical Graphs of Order $\Delta(G)+3$

Combinatorics 2011-03-15 v1

Abstract

Let γt(G)\gamma_t(G) be the total domination number of graph GG, a graph GG is kk-total domination vertex critical (or\ just\ kk-γt\gamma_t-critical) if γt(G)=k\gamma_t(G)=k, and for any vertex vv of GG that is not adjacent to a vertex of degree one, γt(Gv)=k1\gamma_t(G-v)=k-1. Mojdeh and Rad \cite{MR06} proposed an open problem: Does there exist a 3-γt\gamma_t-critical graph GG of order Δ(G)+3\Delta(G)+3 with Δ(G)\Delta(G) odd? In this paper, we prove that there exists a 3-γt\gamma_t-critical graph GG of order Δ(G)+3\Delta(G)+3 with odd Δ(G)9\Delta(G)\geq 9.

Keywords

Cite

@article{arxiv.1103.2415,
  title  = {On the 3-$\gamma_t$-Critical Graphs of Order $\Delta(G)+3$},
  author = {Haoli Wang and Xirong Xu and Yang Yuansheng and Lei Wang},
  journal= {arXiv preprint arXiv:1103.2415},
  year   = {2011}
}

Comments

This paper was accpted by Utilitas Mathematica in 2008