2021/09/11 by Volta, Francesca Dalla, Lucchini, Andrea · 1 citation
#FOS: Mathematics #Group Theory (math.GR)
paper · doi:10.48550/arxiv.2109.05260
The Möbius function of the subgroup lettice of a finite group G has been introduced by Hall and applied to investigate several different questions. We propose the following generalization. Let A be a subgroup of the automorphism group \rmAut(G) of a finite group G and denote by \mathcal CA(G) the set of A-conjugacy classes of subgroups of G. For H≤ G let [H]A~=~\~Ha ~| ~a∈ ~A\ be the element of \mathcal CA(G) containing H. We may define an ordering in \mathcal CA(G) in the following way: [H]A≤ [K]A if Ha≤ K for some a∈ A. We consider the Möbius function μA of the corresponding poset and analyse its properties and possible applications.