Speaker: Emilie Dufresne (Durham)
Title: Separating invariants and local cohomology
Abstract: The study of separating invariants is a new
trend in Invariant Theory and a return to its roots: invariants as a
classification tool. For a finite group acting linearly on a vector
space, a separating set is simply a set of invariants whose elements
separate the orbits of the action. Such a set need not generate the
ring of invariants. In this talk, we give lower bounds on the size of
separating sets based on the geometry of the action. These results are
obtained via the study of the local cohomology with support at an
arrangement of linear subspaces naturally arising from the action.
(Joint with Jack Jeffries)