Twin minus total domination numbers in directed graphs
| Autor: | Nasrin Dehgardi, Maryam Atapour |
|---|---|
| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Discussiones Mathematicae Graph Theory, Vol 37, Iss 4, Pp 989-1004 (2017) |
| ISSN: | 2083-5892 1234-3099 |
| DOI: | 10.7151/dmgt.1983 |
| Popis: | Let D = (V,A) be a finite simple directed graph (shortly, digraph). A function f : V → {−1, 0, 1} is called a twin minus total dominating function (TMTDF) if f(N−(v)) ≥ 1 and f(N+(v)) ≥ 1 for each vertex v ∈ V. The twin minus total domination number of D is y*mt(D) = min{w(f) | f is a TMTDF of D}. In this paper, we initiate the study of twin minus total domination numbers in digraphs and we present some lower bounds for y*mt(D) in terms of the order, size and maximum and minimum in-degrees and out-degrees. In addition, we determine the twin minus total domination numbers of some classes of digraphs. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|