CUNY Graduate Center Differential Geometry Seminar presents

"Spin Manifolds, Einstein metrics, and Differential Topology"

Claude LeBrun

SUNY Stony Brook

Wednesday, October 10

2:30-3:30 pm, Room 4422

I will show that there exist smooth, simply connected, four-dimensional spin manifolds which do not admit Einstein metrics, but nonetheless satisfy the strict Hitchin-Thorpe inequality. The same methods also allow one to easily construct many topological 4-manifolds which admit an Einstein metric for one smooth structure, but which have infinitely many other smooth structures for which no Einstein metric can exist.

claude@math.sunysb.edu

http://www.math.sunysb.edu/~claude/