## Geometry Seminar

**Date:** November 10, 2017

**Time:** 4:00PM - 5:00PM

**Location:** BLOC 628

**Speaker:** Alicia Harper, Brown University

**Title:** *Factorization of maps of Deligne-Mumford stacks*

**Abstract:** The weak factorization theorem provides a tool for explicitly relating birational varieties by a sequence of smooth blowups and blowdowns. In the setting of Deligne-Mumford stacks, one can hope to do something similar, but first one has to grapple with the fact that stacks also carry a local group structure, and thus one needs to use root stacks, a geometric operation that only exists in the stacky world, in addition to blowups and blowdowns. In this talk I will give a - not too technical - introduction to the above concepts, then discuss how to actually go about proving a stacky weak factorization theorem for non-representable morphisms.