3:45PM: Changing Views on Curves and SurfacesBernd SturmfelsWe present work with Kathlen Kohn and Matthew Trager on visual events in computer vision. Given an algebraic curve or surface in 3space, the image or contour curve arises by projecting from a viewpoint. Qualitative changes in that curve occur when the viewpoint crosses the visual event surface. The components of this ruled surface are iterated singular loci of the coisotropic hypersurfaces associated with the original curve or surface. We present formulas, due to Salmon and Petitjean, for the degrees of these surfaces, and show how to compute visual event surfaces using algebraic tools.

5:00PM: Evolutions and Second Symbolic PowersJana SotakovaLet K be a field and let R be a local Kalgebra. An evolution of R is a surjective homomorphism T>R of Kalgebras such that the induced map between the modules of differentials is an isomorphism. We will see that the question of the existence of nontrivial evolutions is related to the EisenbudMazur conjecture on (second) symbolic powers.
