COLLOQUIUM
DEPARTMENT OF MATHEMATICS AND STATISTICS
OAKLAND UNIVERSITY
ROCHESTER, MICHIGAN 48309
Harm Derksen
University of Michigan
Constructive Invariant Theory
Abstract
If $V$ is a representation of an algebraic group $G$, then $G$ also acts on the ring of polynomial functions on $V$. The invariant ring consists of all polynomials which are invariant under the action of $G$. If $G$ is a reductive group then these invariant rings are finitely generated as an algebra. I will discuss upper bounds for the degrees of a minimal set of homogeneous generators of an invariant ring, and also bounds for the minimal number of generators of an invariant ring. Recently Harlan Kadish showed
that we get much better bounds for the number of generators and the computational complexity of the generators if we allow constructible functions instead of polynomial functions.
Thursday, October 20, 2011
3:00– 4:00 P.M.
372 Science and Engineering Building
(Refreshments at 2:30-3:00 PM in the kitchen area adjacent to 368 SEB)