On the α-index of graphs with pendent paths

In particular, write Bp,q,r be the graph obtained from a complete graph Kp by deleting an edge and attaching paths Pq and Pr to its ends. It is shown that if α∈[0,1) and G is a graph of order n and diameter at least k, thenρα(G)≤ρα(Bn−k+2,⌊k/2⌋,⌈k/2⌉), with equality holding if and only if G=Bn−k+2,⌊k/2⌋,⌈k/2⌉. This result generalizes results of Hansen and Stevanović [5], and Liu and Lu [7].