A characteristic map for compact quantum groups

Abstract

We show that if $G$ is a compact Lie group and $\mathfrak{g}$ is its Lie algebra, then there is a map from the Hopf-cyclic cohomology of the quantum enveloping algebra $U_q(\mathfrak{g})$ to the twisted cyclic cohomology of quantum group algebra $\mathcal{O}(G_q)$. We also show that the Schm\"udgen-Wagner index cocycle associated with the volume form of the differential calculus on the standard Podle\'s sphere $\mathcal{O}(S^2_q)$ is in the image of this map.