Hop total Roman domination in graphs

Autor: H. Abdollahzadeh Ahangar, M. Chellali, S. M. Sheikholeslami, M. Soroudi
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: AKCE International Journal of Graphs and Combinatorics, Vol 20, Iss 1, Pp 73-78 (2023)
Druh dokumentu: article
ISSN: 09728600
2543-3474
0972-8600
DOI: 10.1080/09728600.2023.2184288
Popis: AbstractIn this article, we initiate a study of hop total Roman domination defined as follows: a hop total Roman dominating function (HTRDF) on a graph [Formula: see text] is a function [Formula: see text] such that for every vertex u with f(u) = 0 there exists a vertex v at distance 2 from u with f(v) = 2 and the subgraph induced by the vertices assigned non-zero values under f has no isolated vertices. The weight of an HTRDF is the sum of its function values over all vertices, and the hop total Roman domination number [Formula: see text] equals the minimum weight of an HTRDF on G. We provide several properties on the hop total Roman domination number. More precisely, we show that the decision problem corresponding to the hop total Roman domination problem is NP-complete for bipartite graphs, and we determine the exact value of [Formula: see text] for paths and cycles. Moreover, we characterize all connected graphs G of order n with [Formula: see text] Finally, we show that for every tree T of diameter at least 3, [Formula: see text] where [Formula: see text] is the hop total domination number.
Databáze: Directory of Open Access Journals