Total dominator total coloring of a graph

Abstract

Here, we initiate to study the total dominator total coloring of a graph which is a total coloring of the graph such that each object of the graph is adjacent or incident to every object of some color class. In more details, while in section 2 we present some tight lower and upper bounds for the total dominator total chromatic number of a graphs in terms of some parameters such as order, size, the total dominator chromatic and total domination numbers of the graph and its line graph, in section 3 we restrict our to trees and present a Nordhaus-Gaddum-like relation for trees. Finally in last section we show that there exist graphs that their total dominator total chromatic numbers are equal to their orders.