Spherical orbits and representations of $U_ε(\mathfrak g)$

Cantarini, Nicoletta; Carnovale, Giovanna; Costantini, Mauro

Spherical orbits and representations of $U_ε(\mathfrak g)$

Authors

Cantarini, Nicoletta

Carnovale, Giovanna

Costantini, Mauro

Description

Let $U_ε(\mathfrak g)$ be the simply connected quantized enveloping algebra associated to a finite-dimensional complex simple Lie algebra $\mathfrak g$ at the roots of unity. The De Concini-Kac-Procesi conjecture on the dimension of the irreducible representations of $U_ε(\mathfrak g)$ is proved for representations corresponding to the spherical conjugacy classes of the simply connected algebraic group $G$ with Lie algebra $\mathfrak g$. We achieve this result by means of a new characterization of the spherical conjugacy classes of $G$ in terms of elements of the Weyl group.
This new version includes part I and part II. Some typos are corrected and some remarks are added