On γ-free, γ-totally-free and γ-fixed sets in graphs

Document Type : Original paper

Authors

1 Department of Mathematics, S. D. College, Alappuzha-690 104, India

2 Department of Studies in Mathematics, University of Mysore, Manasagangothri, Mysuru-570 006, India

3 Adjunct Professor, Department of Computer Science and Engineering, Ramco Institute of Technology, Rajapalayam-626 117, Tamil Nadu, India

Abstract

Let G=(V,E) be a connected graph. A subset S of V is called a γ-free set if there exists a γ-set D of G such that SD=. If further the induced subgraph H=G[VS] is connected, then S is called a  cc-γ-free set of G. We use this concept to identify connected induced subgraphs H of a given graph G such that γ(H)γ(G). We also introduce the concept of γ-totally-free and γ-fixed sets and present several basic results on the corresponding parameters. 

Keywords


[1] G. Chartrand, L. Lesniak, and P. Zhang, Graphs & digraphs, CRC, Boca Raton, 2016.
[2] T.W. Haynes, S.T. Hedetniemi, and P.J. Salter, Fundamentals of Domination in Graphs, Marcel Dekker, New York, 1998.
[3] S.M. Hedetniemi, S.T. Hedetniemi, and R. Reynolds, Combinatorial problems on chessboards: II, Domination in Graphs, Advanced Topics (T.W. Haynes, S.T. Hedetniemi, and P.J. Salter, eds.), Marcel Dekker, Inc., New York, 1998, pp. 133–
192.
[4] N. Jafari Rad, D.A. Mojdeh, R. Musawi, and E. Nazari, Total domination in cubic knödel graphs, Commun. Comb. Optim. 6 (2021), no. 2, 221–230.
[5] E. Sampathkumar and P.S. Neeralagi, Domination and neighbourhood critical, fixed, free and totally free points, Indian J. Statistics (1992), 403–407.