Sum Geometric Harmonic Means Index of Graphs.

Let G be a connected graph, the sum geometric - arithmetic means index of G is defined as SGAM (G) = ∑uv ∈E(G) (√(d(u)d(v) )+ (d(v)+d(v))/ 2 ) . In this paper, the concept of sum geometric harmonic means index of a graph G, denoted by SG hm (G) is introduced and SGhm (G) of few families of graphs is computed. Further, we establish the bounds for sum geometric harmonic means index. General Terms: AMS, subject Classification 05C07; 92E10. [ABSTRACT FROM AUTHOR]