Signed total Italian k-domination in digraphs

Document Type : Original paper

Author

Lehrstuhl II für Mathematik, RWTH Aachen University, 52056 Aachen, Germany

Abstract

Let k1 be an integer, and let D be a finite and simple digraph with vertex set V(D). A signed total Italian k-dominating function (STIkDF) on a digraph D is a function f:V(D){1,1,2} satisfying the conditions that (i) xN(v)f(x)k for each vertex vV(D), where N(v) consists of all vertices of D from which arcs go into v, and (ii) each vertex u with f(u)=1 has an in-neighbor v for which f(v)=2 or two in-neighbors w and z with f(w)=f(z)=1. The weight of an STIkDF f is ω(f)=vV(D)f(v). The signed total Italian k-domination number γstIk(D) of D is the minimum weight of an STIkDF on D. In this paper we initiate the study of the signed total Italian k-domination number of digraphs, and we  present different bounds on γstIk(D). In addition, we determine the signed total Italian k-domination number of some classes of digraphs.

Keywords

Main Subjects


[1] J. Amjadi and M. Soroudi, Twin signed total Roman domination numbers in digraphs, Asian-European J. Math. 11 (2018), no. 3, Article ID: 1850034.  https://doi.org/10.1142/S1793557118500341
[2] M. Chellali, N. Jafari Rad, S.M. Sheikholeslami, and L. Volkmann, Roman domination in graphs, Topics in Domination in Graphs (T.W. Haynes, S.T. Hedetniemi, and M.A. Henning, eds.), Springer, Berlin/Heidelberg, 2020, pp. 365–409.
[3] M. Chellali, N. Jafari Rad, S.M. Sheikholeslami, and L. Volkmann, A survey on Roman domination parameters in directed graphs, J. Combin. Math. Combin. Comput. 115 (2020), 141–171.
[4] M. Chellali, N. Jafari Rad, S.M. Sheikholeslami, and L. Volkmann, Varieties of Roman domination II, AKCE Int. J. Graphs Comb. 17 (2020), no. 3, 966–984.https://doi.org/10.1016/j.akcej.2019.12.001
[5] M. Chellali, N. Jafari Rad, S.M. Sheikholeslami, and L. Volkmann, Varieties of Roman domination, Structures of Domination in Graphs (T.W. Haynes, S.T. Hedetniemi, and M.A. Henning, eds.), Springer, Berlin/Heidelberg, 2021, pp. 273–307.
[6] E.J. Cockayne, P.A. Dreyer Jr, S.M. Hedetniemi, and S.T. Hedetniemi, Roman domination in graphs, Discrete Math. 278 (2004), no. 1-3, 11–22.  https://doi.org/10.1016/j.disc.2003.06.004
[7] N. Dehgardi and L. Volkmann, Signed total Roman k-domination in directed graphs, Commun. Comb. Optim. 1 (2016), no. 2, 165–178.  https://doi.org/10.22049/cco.2016.13576
[8] F. Harary, R.Z. Norman, and D. Cartwright, Structural models: An introduction to the theory of directed graphs, Wiley, New York, 1965.
[9] T.W. Haynes, S.T. Hedetniemi, and P.J. Slater, Fundamentals of Domination in Graphs, Marcel Dekker, Inc., New York, 1998.
[10] L. Volkmann, On the signed total Roman domination and domatic numbers of graphs, Discrete Appl. Math. 214 (2016), 179–186.  https://doi.org/10.1016/j.dam.2016.06.006
[11] L. Volkmann, Signed total Roman domination in graphs, J. Comb. Optim. 32 (2016), 855–871.  https://doi.org/10.1007/s10878-015-9906-6
[12] L. Volkmann, Signed total Roman domination in digraphs, Discuss. Math. Graph Theory 37 (2017), no. 1, 261–272. http://doi.org/10.7151/dmgt.1929
[13] L. Volkmann, Signed total Roman k-domination in graphs, J. Combin. Math. Combin. Comput. 105 (2018), 105–116.
[14] L. Volkmann, Signed total Italian domination in graphs, J. Combin. Math. Combin. Comput. 115 (2020), 291–305.
[15] L. Volkmann, Signed total Italian k-domination in graphs, Commun. Comb. Optim. 6 (2021), no. 2, 171–183.  https://doi.org/10.22049/cco.2020.26919.1164
[16] L. Volkmann, Signed total Italian domination in digraphs, Commun. Comb. Optim. 8 (2023), no. 3, 457–466.  https://doi.org/10.22049/cco.2022.27700.1318