  The goal is to understand the index-theoretic aspects of the recent preprint
of R. Nest and F. Radulescu, math.OA/9911042. The basic observation (due to E.
Guenter/N. Higson) is that the index of the Toeplitz operator is equal to the
index of an associated Callias type operator, i.e. a Dirac operator with
potential, the index of which is easy to compute. We show how to extend this
idea to the equivariant case.
