Martin Pinsonnault (Ontario) will talk in the geometry seminar on 23rd June, at 2pm in the Salle des Profs. Martin’s title is “Symplectic balls in CP^2, configuration spaces, and root systems.” and his abstract is below.
Understanding the space of symplectic embeddings of n standard balls into a symplectic manifold is a very hard problem for which very little is understood. In this talk, I will show that in the case of CP^2, these spaces are homotopy equivalent to the configuration space of n points provided the sum of the capacities of the balls is less than the area of a line. I will then explain why, for n=9, there are infinitely many changes in the homotopy types of the embedding spaces as the capacities increase, and how this relates to Moses’ number game on directed graphs.