Аннотация:
I will discuss Grothendieck resolutions related to semisimple Lie algebras and relevant systems of flops and other birational transformations. Then I describe a Schober of a Grothendieck resolution, i.e. a categorified perverse sheaf on the complex vector space stratified by a system of hyperplanes of Dynkin type. This is a joint work with M. Kapranov and V. Schechtman.