The Roman k-domatic Number of a Graph
The Roman k-domatic Number of a Graph作者机构:Department of Mathematics Azarbaijan University of Tarbiat MoaUem Tabriz 53714-161 L R. Iran and School of Mathematics Institute for Research in Fundamental Sciences ( IPM) Lehrstuhl H fiir Mathematik RWTH Aachen University 52056 Aachen Germany
出 版 物:《Acta Mathematica Sinica,English Series》 (数学学报(英文版))
年 卷 期:2011年第27卷第10期
页 面:1899-1906页
核心收录:
学科分类:07[理学] 08[工学] 080203[工学-机械设计及理论] 0802[工学-机械工程] 0701[理学-数学] 070101[理学-基础数学]
基 金:IPM
主 题:Roman domination number Roman domatic number Roman k-domination number Ro- man k-domatic number
摘 要:Let k be a positive integer. A Roman k-dominating function on a graph G is a labeling f : V(G) → {0, 1, 2} such that every vertex with label 0 has at least k neighbors with label 2. A set {f1, f2,..., fd} of distinct Roman k-dominating functions on G with the property that ∑di=1 fi(v) ≤ 2 for each v C V(G), is called a Roman k-dominating family (of functions) on G. The maximum number of functions in a Roman k-dominating family on G is the Roman k-domatic number of G, denoted by dkR(G). Note that the Roman 1-domatic number dlR(G) is the usual Roman domatic number dR(G). In this paper we initiate the study of the Roman k-domatic number in graphs and we present sharp bounds for dkR(G). In addition, we determine the Roman k-domatic number of some graphs. Some of our results extend those given by Sheikholeslami and Volkmann in 2010 for the Roman domatic number.