The Randic index and the diameter of graphs

Yiting Yang, Linyuan Lu

The {\it Randić index} $R(G)$ of a graph $G$ is defined as the sum of 1/\sqrt{d_ud_v} over all edges $uv$ of $G$, where $d_u$ and $d_v$ are the degrees of vertices $u$ and $v,$ res…