a1 School of Mathematics and Statistics University of Sheffield The Hicks Building Sheffield S3 7RH, UK
Rings of invariants are identified for some automorphisms θ of certain iterated skew polynomial rings R, including the enveloping algebra of sl2(k), the Weyl algebra A1 and their quantizations. We investigate how finite-dimensional simple R-modules split over the ring of invariants Rθ and how finite-dimensional simple Rθ-modules extend to R.
(Received June 06 1994)
* With the support of a University of Sheffield Postgraduate Research Scholarship