1. Department of Mathematics, Washington University, St. Louis, MO, 63130, USA 2. Department of Mathematics, Ohio State University, 100 Math Tower, 231 West 18th Ave., Columbus, OH, 43210, USA
Abstract:
Let H be an extension of a finite group Q by a finite group G. Inspired by the results of duality theorems for étale gerbes on orbifolds, the authors describe the number of conjugacy classes of H that map to the same conjugacy class of Q. Furthermore, a generalization of the orthogonality relation between characters of G is proved.