3 research outputs found
Some Steiner concepts on lexicographic products of graphs
The smallest tree that contains all vertices of a subset ▫▫ of ▫▫ is called a Steiner tree. The number of edges of such a tree is the Steiner distance of ▫▫ and union of all Steiner trees of ▫▫ form a Steiner interval. Both of them are described for the lexicographic product in the present work. We also give a complete answer for the following invariants with respect to the Steiner convexity: the Steiner number, the rank, the hull number, and the Carathéodory number, and a partial answer for the Radon number. At the end we locate and repair a small mistake from [J. Cáceres, C. Hernando, M. Mora, I. M. Pelayo, M. L. Puertas, On the geodetic and the hull numbers in strong product graphs, Comput. Math. Appl. 60 (2010) 3020--3031]