Tree Domination in Graphs

Xuegang Chen1,2, Liang Sun3, Alice McRae4
1Department of Applied Mathematics, Beijing Institute of Technology, Beijing 100081, P.R. China
2The College of Information Science and Engineering, Shandong University of Science and Technology, Taian, Shandong Province 271019, P.R. China
3Department of Applied Mathematics, Beijing Institute of Technology, Beijing 100081, P.R. China;
4Department of Computer Science, Appalachian State University, Boone, North Carolina

Abstract

A subset \(S\) of \(V(G)\) is called a dominating set if every vertex in \(V(G) – S\) is adjacent to some vertex in \(S\). The domination number \(\gamma(G)\) of \(G\) is the minimum cardinality taken over all dominating sets of \(G\). A dominating set \(S\) is called a tree dominating set if the induced subgraph \(\langle S\rangle\) is a tree. The tree domination number \(\gamma_{tr}(G)\) of \(G\) is the minimum cardinality taken over all minimal tree dominating sets of \(G\). In this paper, some exact values of tree domination number and some properties of tree domination are presented in Section [2]. Best possible bounds for the tree domination number, and graphs achieving these bounds are given in Section [3]. Relationships between the tree domination number and other domination invariants are explored in Section [4], and some open problems are given in Section [5].