A&NT seminar: David Rydh

David Rydh (KTH) will give an algebra and number theory seminar. 

Title: Local structure of algebraic stacks and applications

Abstract:
Algebraic stacks generalize equivariant algebraic geometry: the action of an algebraic group on a scheme. Some natural moduli problems, such as moduli of sheaves and moduli of singular curves, give rise to stacks with infinite stabilizers. The local structure theorem states that many such stacks locally look like the quotient of a scheme by a group action. This is related to Luna's slice theorem in equivariant geometry.

I will also mention some applications such as compact generation of derived categories, criteria for the existence of good moduli spaces, BB-decompositions for stacks, Kirwan partial desingularization and generalized Donaldson--Thomas invariants.