The Steiner Wiener index of trees with a given segment sequence

The Steiner distance of vertices in a set S is the minimum size of a connected subgraph that contain these vertices. The sum of the Steiner distances over all sets S of cardinality k is called the Steiner k-Wiener index and studied as the natural generalization of the famous Wiener index in chemical graph theory. In this paper we study the extremal structures, among trees with a given segment sequence, that maximize or minimize the Steiner k-Wiener index. The same extremal problems are also considered for trees with a given number of segments.