  The classical Frobenius-Schur indicators for finite groups are character sums
defined for any representation and any integer m greater or equal to 2. In the
familiar case m=2, the Frobenius-Schur indicator partitions the irreducible
representations over the complex numbers into real, complex, and quaternionic
representations. In recent years, several generalizations of these invariants
have been introduced. Bump and Ginzburg, building on earlier work of Mackey,
have defined versions of these indicators which are twisted by an automorphism
of the group. In another direction, Linchenko and Montgomery have defined
Frobenius-Schur indicators for semisimple Hopf algebras. In this paper, the
authors construct twisted Frobenius-Schur indicators for semisimple Hopf
algebras; these include all of the above indicators as special cases and have
similar properties.
