On Second Geometric-Arithmetic Index of Graphs

Document Type : Research Paper


1 Sungkyunkwan University, Republic of Korea

2 University of Kragujevac, Serbia


The concept of geometric-arithmetic indices (GA) was put forward in chemical graph theory very recently. In spite of this, several works have already appeared dealing with these indices. In this paper we present lower and upper bounds on the second geometric-arithmetic index (GA2) and characterize the extremal graphs. Moreover, we establish Nordhaus-Gaddum-type results for GA2.