q-deformation of $z\to \frac{az+b}{cz+d}$

Abstract

We construct the action of the quantum double of $\uq$ on the standard Podleś sphere and interpret it as the quantum projective formula generalizing to the q-deformed setting the action of the Lorentz group of global conformal transformations on the ordinary Riemann sphere.

LaTeX, 16 pages, we add a reference where an alternative construction of the q-Lorentz group action on the Podles sphere is given