Some eigenvalue properties in graphs (conjectures of Graffiti. II)
Discrete Mathematics
Discrete Mathematics
Graph Theory
On the Randić index and girth of graphs
Discrete Applied Mathematics
Hi-index | 0.04 |
The Randic index R(G) of a graph G is defined by R(G)=@?"u"v1d(u)d(v), where d(u) is the degree of a vertex u in G and the summation extends over all edges uv of G. Aouchiche, Hansen and Zheng proposed the following conjecture: For any connected graph on n=3 vertices with Randic index R and girth g, R+g=n-3+2n-1+72andR@?g=3n-9+32n-1+32 with equalities if and only if G=S"n^+. This paper is devoted to giving a confirmative proof to this conjecture.