The bismash product $H_n = mathbb C^{C_n}#mathbb CS_{n−1}$ and its dual $J_n = mathbb C^{S_{n−1}}#mathbb CC_n$ are semisimple Hopf algebras whose structure is induced from a factorization of the symmetric group $S_n = C_n S_{n−1}$ . It is known that the indicators of all simple modules of $H_n$ are +1 [JM]. In this talk, we describe the representation theory of $J_n$ and how permutations in the symmetric group were used to prove that the algebraic dual $J_n$ can have negative indicators. Specifically we list the conditions under which simple modules of $J_n$ can have negative indicators and describe how we are able to count them. 

https://indico.math.cnrs.fr/event/8813/