June 10, 2023 # Doost Ali Mojdeh

Degree: Professor
Address: Department of Mathematics, University of Mazandaran, Babolsar, Iran
Education: Ph.D in Mathematics (Graph Theory and Combinatorics)
Phone: 011-35302448
Faculty: Faculty of Mathematical Sciences

## Research

 Title Bounds on double Roman domination number of graphs Type Presentation Keywords Double Roman domination, bounds on double Roman graph, dominant differential Researchers a { color: #4f98b0; } a:hover { color: #ffab00; } a:link:visited { text-decoration: none; } Doost Ali Mojdeh (First researcher) , Ali Parsian (Second researcher) , Iman Masoumi (Third researcher)

## Abstract

Let G = (V, E) be a simple graph. A double Roman dominating function of a graph G is a function {0,1,2,3} :  V f having the property that if 0 = ) (v f , then the vertex v must have at least two neighbors 1 w , 2w such that 2 = ) ( = ) ( 1 2 w f w f or one neighbor w such that 3 = ) (w f ; and if 1=) (v f , then the vertex v must have at least one neighbor w such that f (w)  2 . The weight of a double Roman dominating function is the sum = ( ) ( ) w f v f v V G  , and the minimum weight of f w for every double Roman dominating function f on G is called double Roman domination number of G . We denote this number with ) (G dR  . In this paper; we obtain some new lower and upper bounds of double Roman domination number of graphs.