SURVEY ON THE GENERAL RANDIC INDEX: EXTREMAL RESULTS AND BOUNDS

For a is an element of R, the general Randic index of a graph G is defined as R-a(G) = Sigma(uv is an element of E)(G)[d(u)d( v)]alpha, where E(G) is the edge set of G, and d(u) and d(v) are the degrees of vertices u and v in G, respectively. We give a survey containing known extremal results about the general Randi ' c index. We present results for general graphs, trees, unicyclic graphs, bicyclic graphs and chemical graphs.