Title: On cohomology of BG.Abstract: Cohomology of classifying space/stack of a group G is the home which resides all characteristic classes of G-bundles/torsors. In this talk, we will try to explain some results on Hodge/de Rham cohomology of BG where G is a p-power order commutative group scheme over a perfect field of characteristic p, in terms of […]

Title: On the strong Sarkisov Program.Abstract: In this talk, I will explain some results about factorizing a birational map between Mori fibre spaces into Sarkisov links, such that the invariants of Sarkisov will decrease. I will explain that such problem is closely related to the termination of certain log flips in lower dimension.

Title: Unipotent homotopy theory of schemes.Abstract: In this talk, I will present a notion of unipotent homotopy theory for schemes, which is based on Toen's work on affine stacks. I will discuss some general properties of the resulting unipotent homotopy group schemes and explain how over a field of characteristic p>0, they often recover the unipotent completion […]