On Some closed operations in threshold graphs

Abstract

This paper is discussing threshold graph. Threshold graph have numerous applications in diverse areas which include computer science and psychology. A threshold graph can be constructed through by repeated application starts with a single vertex, at each step, either a dominating vertex is added, or an isolated vertex is added. The purpose of this paper is to apply some graph operations in a threshold graph and investigating the new graph as result of those operations whether the resulting graph is still a threshold graph or not. We also construct its creation sequence generally.By applying some operations which are given at threshold graph, we can conclude that for union, intersection, ring sum and complement graph, the new graphs are still threshold graphs. Otherwise for the join, the new graphs is not threshold graphs. The creation sequence is achieved generally for each operation.