On the extremal total irregularity index of n-vertex trees with fixed maximum degree

Document Type : Original paper


Fast NUCES, Lahore, Pakistan.


In the extension of irregularity indices, Abdo et. al. [1] defined the total irregu-

larity of a graph G = (V, E) as irrt(G) = 21 Pu,v∈V (G) du − dv , where du denotes

the vertex degree of a vertex u ∈ V (G). In this paper, we investigate the total
irregularity of trees with bounded maximal degree Δ and state integer linear pro-
gramming problem which gives standard information about extremal trees and it
also calculates the index.


Main Subjects