Tim Ryan : An introduction to stacks

Posted by Tim Ryan , part of the Graduate Algebraic Geometry Seminar.

At

Dec. 2, 2015, 3 p.m.

In

SEO 712

Abstract

Assuming a working knowledge of category theory and scheme theory, we will introduce stacks. First, we will motivate them from the perspective of moduli theory. We will then see how they are a natural generalization of sheaves using the definition of a stack as a functor. Following this, we will redefine stacks in the more standard way (as categories) and will proceed to define Deligne-Mumford and Artin stack. Finally, we will conclude with a couple brief examples.