Graduate Student Colloquium
Ian Agol
UIC
The topology of the universe
Abstract: According to Einstein's theory of general
relativity, our universe is a (Lorentzian) Einstein 4-manifold.
Einstein manifolds are Lorentzian manifolds whose
local structure is determined by the Einstein's field
equations, but the global structure is not determined.
This leaves open the possibility that the universe has
non-trivial topology. We'll discuss the socalled Friedman
universes, which are topologically a homogeneous 3-manifold
cross R, and seem to be the most prevalent model used by
cosmologists for the global structure of the universe. We'll then
discuss how cosmologists hope to discover
the topology of the universe, and focus on some of the
simplified mathematical ideas that have arisen in their
work.
Weekly tea at 4:15 in 300 SEO
Friday September 23, 2005 at 3:00 PM in SEO 636