Semi-invariants of quiver representations and partially ordered sets.
Jerzy Weyman

Abstract: I will discuss the basic notions related to semi-invariants of quiver representations and partially ordered sets. In the case of quivers with no relations the rings of semi-invariants can be calculated explicitly for the finite type and tame quivers. Moreover, for the finite type quivers these rings are always polynomial rings, for tame quivers they are either polynomial rings or hypersurface rings.
I will discuss the current research related to Kristin's thesis. The object is to generalize these results to a related case of representations of partially ordered sets. It seems that the analogous statements could hold. Some preliminary results are already established, but the general picture is still not completely clear.