Adjacency Spectrum of Reduced Power Graphs of Finite Groups

The reduced power graph of a group [Formula: see text], denoted by [Formula: see text], is the graph whose vertex set is the set of all elements of [Formula: see text] and two vertices [Formula: see text] and [Formula: see text] are adjacent in [Formula: see text] if and only if [Formula: see text] or [Formula: see text]. In this paper, we study the adjacency spectrum of the reduced power graph of [Formula: see text], [Formula: see text], [Formula: see text], dihedral group, quaternion group and semi-dihedral group.