Computing GA4 Index of Some Graph Operations

The geometric-arithmetic index is another topological index was defined as2 deg ( )deg ( )( )deg ( ) deg ( )g guv eg gu vga gu v? ? ??, in which degree of vertex u denoted by degg (u). wenow define a new version of ga index as 4( )2 ? ( )? ( )( )? ( ) ? ( )g ge uv e g g gu vga gu v ? ?? ??, where ?g(u) isthe eccentricity of vertex u. in this paper we compute this new topological index for twograph operations.