关键词: 二面体群, 正规子群包含图, 图的谱, 邻接谱, （拟）拉普拉斯谱

Abstract: In this paper, a class of simple undirected graphs called normal subgroup inclusion graphs are constructed by using the nontrivial normal subgroups of finite groups as its vertex set, and the two vertices K and H of the graph are adjacent if and only if H?K or K?H. In this paper, the spectral of normal subgroup inclusion graphs In(D2n) of some special dihedral groups D2n are studied, and the adjacency spectra, Laplacian spectra and quasi-Laplacian spectra of these graphs are obtained.