BOUNDS ON RZ-INVARIANT OF GRAPHS

Abstract

The RZ-invariant of a simple connected graph G is defined as the sum of the terms (Deg(u) + Deg(v) − 2)² over all edges uv of G, where Deg(u) is the degree of a vertex u in G. In this paper, we obtain some new upper and lower bounds for the RZ-invariant in terms of other graph parameters.