On pointed Hopf algebras associated to unmixed conjugacy classes in S_n
arXiv:math/0608701 · doi:10.1063/1.2436730
Abstract
Let s in S_n be a product of disjoint cycles of the same length, C the conjugacy class of s and rho an irreducible representation of the isotropy group of s. We prove that either the Nichols algebra B(C, rho) is infinite-dimensional, or the braiding of the Yetter-Drinfeld module is negative.