The kth power of a graph G, denoted by Gk , is a graph with the same vertex set as G such that two vertices are adjacent in Gk if and only if their distance is at most k in G. The Wiener index is a distance-based topological index defined as the sum of distances between all pairs of vertices in a graph. In this note, we give the bounds on the Wiener index of the graph Gk . The Nordhaus–Gaddum-t...

The Wiener index of a connected graph is the sum of topological distances between all pairs of vertices. Since Wang in [23] gave a mistake result on the maximum Wiener index for given tree degree sequence, in this paper, we investigate the maximum Wiener index of trees with given degree sequences and extremal trees which attain the maximum value.

The Wiener index of a graph is the sum of all pairwise distances of vertices of the graph. In this paper we characterize the trees which minimize the Wiener index among all trees of given order and maximum degree and the trees which maximize the Wiener index among all trees of given order that have only vertices of two di erent degrees.

objective: peripheral arterial disease (pad) is a state characterized by atherosclerotic occlusive disease of lower extremities. diabetes is the main risk factor for pad. material and methods: to assess the prevalence of pad, a cross sectional study was performed on 352 diabetic patients who referred to yazd diabetes research center from 2007 to 2010. vascular assessment was done by measuring t...

In the drug design process, one wants to construct chemical compounds with certain properties. In order to establish the mathematical basis for the connections between molecular structures and physicochemical properties of chemical compounds, some so-called structure-descriptors or ”topological indices” have been put forward. Among them, the Wiener index is one of the most important. A long sta...

The Wiener index of a graph G, denoted W(G), is the sum distances between all non-ordered pairs vertices in G.É. Czabarka, et al. conjectured that for simple quadrangulation G on n vertices, n?4, W(G)?112n3+76n?2,n?0(mod2), 112n3+1112n?1,n?1(mod2).In this paper, we confirm conjecture.

In theoretical chemistry, -modified Wiener index is a graph invariant topological index to analyze the chemical properties of molecular structure. In this note, we determine the minimum -modified Wiener index of graph with fixed connectivity or edge-connectivity. Our results also present the sufficient and necessary condition for reaching the lower bound.