The signed star domination numbers of the Cartesian product graphs Original Research Article

Let G be a graph with vertex set image and edge set image. A function image is said to be a signed star dominating function of G if image for every image, where image. The minimum of the values of image, taken over all signed star dominating functions f on image, is called the signed star domination number of G and is denoted by image. In this paper, a sharp upper bound of image is presented.