Mixed Roman Domination in Graphs

Let $$G = (V, E)$$G=(V,E) be a simple graph with vertex set V and edge set E. A mixed Roman dominating function (MRDF) of G is a function $$f: V\cup E\rightarrow \{0,1,2\}$$f:V∪E→{0,1,2} satisfying the condition every element $$x\in V\cup E$$x∈V∪E for which $$f(x)= 0$$f(x)=0 is adjacent or incident to at least one element $$y\in V\cup E$$y∈V∪E for which $$f(y) = 2$$f(y)=2. The weight of a MRDF f is $$\omega (f)=\sum _{x\in V\cup E}f(x)$$ω(f)=∑x∈V∪Ef(x). The mixed Roman domination number of G is the minimum weight of a mixed Roman dominating function of G. In this paper, we initiate the study of the mixed Roman domination number and we present bounds for this parameter. We characterize the graphs attaining an upper bound and the graphs having small mixed Roman domination numbers.

[1]  M. Chellali,et al.  A NOTE ON THE INDEPENDENT ROMAN DOMINATION IN UNICYCLIC GRAPHS , 2012 .

[2]  Yousef Alavi,et al.  Total matchings and total coverings of graphs , 1977, J. Graph Theory.

[3]  Nader Jafari Rad,et al.  AUSTRALASIAN JOURNAL OF COMBINATORICS Volume 52 (2012), Pages 11–18 Properties of independent Roman domination in graphs ∗ , 2022 .

[4]  J. M. Sigarreta,et al.  The differential and the roman domination number of a graph , 2014 .

[5]  Pooya Hatami,et al.  An approximation algorithm for the total covering problem , 2010, Discuss. Math. Graph Theory.

[6]  Jianfang Wang,et al.  On total covers of graphs , 1992, Discret. Math..

[7]  Peter J. Slater,et al.  Fundamentals of domination in graphs , 1998, Pure and applied mathematics.

[8]  Gerard J. Chang,et al.  On the mixed domination problem in graphs , 2013, Theor. Comput. Sci..

[9]  I. Stewart Defend the Roman Empire , 1999 .

[10]  Stephen T. Hedetniemi,et al.  Roman domination in graphs , 2004, Discret. Math..

[11]  Charles S. Revelle,et al.  Defendens Imperium Romanum: A Classical Problem in Military Strategy , 2000, Am. Math. Mon..

[12]  Nader Jafari Rad,et al.  Strong Equality Between the Roman Domination and Independent Roman Domination Numbers in Trees , 2013, Discuss. Math. Graph Theory.

[13]  D. West Introduction to Graph Theory , 1995 .

[14]  Paul Erdös,et al.  On total matching numbers and total covering numbers of complementary graphs , 1977, Discret. Math..

[15]  Stephen T. Hedetniemi,et al.  A Linear Algorithm for the Domination Number of a Tree , 1975, Inf. Process. Lett..

[16]  Yancai Zhao,et al.  The algorithmic complexity of mixed domination in graphs , 2011, Theor. Comput. Sci..