Properties of Total Restrained Domination Vertex Critical Graphs

Nader Jafari Rad1,2
1Department of Mathematics, Shahrood University of Technology, Shahrood, Iran
2School of Mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5746, Tehran, Iran

Abstract

A graph \(G\) with no isolated vertex is total restrained domination vertex critical if for any vertex \(v\) of \(G\) that is not adjacent to a vertex of degree one, the total restrained domination number of \(G – v\) is less than the total restrained domination number of \(G\). We call these graphs \(\gamma_{tr}\)-vertex critical. If such a graph \(G\) has total restrained domination number \(k\), then we call it \(k\)-\(\gamma_{tr}\)-vertex critical. In this paper, we study some properties in \(\gamma_{tr}\)-vertex critical graphs of minimum degree at least two.