Actions of quantum linear spaces on quantum algebras

Quantum Lens Spaces and Principal Actions on Graph C-Algebras

We study certain principal actions on noncommutative C-algebras. Our main examples are the Zpand T-actions on the odd-dimensional quantum spheres, yielding as fixed-point algebras quantum lens spaces and quantum complex projective spaces, respectively. The key tool in our analysis is the relation of the ambient C-algebras with the Cuntz-Krieger algebras of directed graphs. A general result abou...

Reiter’s Properties for the Actions of Locally Compact Quantum Goups on von Neumann Algebras

reiter’s properties for the actions of locally compact quantum goups on von neumann algebras

Lifting of Quantum Linear Spaces

We propose the following principle to study pointed Hopf algebras, or more generally, Hopf algebras whose coradical is a Hopf subalgebra. Given such a Hopf algebra A, consider its coradical filtration and the associated graded coalgebra grA. Then grA is a graded Hopf algebra, since the coradical A0 of A is a Hopf subalgebra. In addition, there is a projection π : grA → A0; let R be the algebra ...

Ergodic Actions of Universal Quantum Groups on Operator Algebras

We construct ergodic actions of compact quantum groups on C∗-algebras and von Neumann algebras, and exhibit phenomena of such actions that are of different nature from ergodic actions of compact groups. In particular, we construct: (1). an ergodic action of the compact quantum Au(Q) on the type IIIλ Powers factor Rλ for an appropriate positive Q ∈ GL(2, R); (2). an ergodic action of the compact...