Croatica Chemica Acta, Vol. 80 No. 2, 2007.
Izvorni znanstveni članak
Comparing the Zagreb Indices
Pierre Hansen
Damir Vukičević
Sažetak
Let G = (V, E) be a simple graph with n = |V | vertices and m = |E | edges; let d1, d2, …, dn denote the degrees of the vertices of G. If Δ= maxdi ≤ 4, G is a chemical graph. The first and second Zagreb indices are defined as
M1 = Σdi ²and M2 = Σd i d j
We show that for all chemical graphs M 1/n ≤ M2/m. This does not hold for all general graphs, connected or not.
Ključne riječi
extremal graph; Zagreb index; AGX; chemical graphs
Hrčak ID:
12846
URI
Datum izdavanja:
12.6.2007.
Posjeta: 1.649 *