%0 Journal Article
%T Twin minus domination in directed graphs
%J Communications in Combinatorics and Optimization
%I Azarbaijan Shahid Madani University
%Z 2538-2128
%A Atapour, Maryam
%A Khodkar, Abdollah
%D 2016
%\ 12/01/2016
%V 1
%N 2
%P 149-164
%! Twin minus domination in directed graphs
%K twin domination in digraphs
%K minus domination in graphs
%K twin minus domination in digraphs
%R 10.22049/cco.2016.13575
%X Let $D=(V,A)$ be a finite simple directed graph. A function $f:Vlongrightarrow {-1,0,1}$ is called a twin minus dominating function if $f(N^-[v])ge 1$ and $f(N^+[v])ge 1$ for each vertex $vin V$. The twin minus domination number of $D$ is $gamma_{-}^*(D)=min{w(f)mid f mbox{ is a twin minus dominating function of } D}$. In this paper, we initiate the study of twin minus domination numbers in digraphs and present some lower bounds for $gamma_{-}^*(D)$ in terms of the order, size and maximum and minimum in-degrees and out-degrees.
%U http://comb-opt.azaruniv.ac.ir/article_13575_b0af46e588dfc0fa0951f816023dd6df.pdf