Department Colloquium

Abstract: Solutions to Einstein's equations of general relativity can display two fundamentally different types of behavior: dispersion and gravitational collapse to a black hole. The threshold between these two phases in the moduli space of solutions is numerically well-studied, but little is known mathematically. In this talk, I will explain the unexpected role that extremal (maximally spinning or charged) black holes play in this story and discuss some recent theorems and conjectures. This is based on joint work with Yannis Angelopoulos (University of Crete) and Christoph Kehle (University of Zürich).