“…The extremal problems for the largest and the second largest α-eigenvalues were studied in [8,17,23,24,28,29]. Many graph operations such as disjoint union, corona, edge corona, neighborhood corona, common neighborhood graphs, have been introduced and their spectral properties have been studied, see [1,3,5,9,10,12,14,15,16,18,19,26]. Several variants of corona product and duplicate of two graphs have been introduced and their spectra are computed.…”