Fullness of connes spectra and the connes hopf kernel

Abstract

Let H be a finite dimensional, semisimple Hopf algebra over a field K and let A be an H- module algebra. Assume K is a splitting field for H and that H is strongly semiprime. If A is H- semiprime, we show the Connes spectrum of H acting on A consists of all of the irreducible representations of H is equivalent to every nonzero annihilator ideal of the smash product meets A nontrivially. If H is also cocommutative, we let I^′ be the intersection of the annihilators of the modules in the Connes spectrum. We find some of the information encoded in the Hopf kernel of the natural map from H to H/I^′.

1991 Mathematics Subject Classafication.:

• Primary 16W30
• Secondary 16W20

Keywords:

• Connes spectrum
• Hopf algebra actions
• Hopf kernel.