H-cobordisms and corks

Geometry Topology Student Seminar
Wednesday, October 2, 2019 - 2:00pm for 1 hour (actually 50 minutes)
Skiles 006
Agniva Roy – Georgia Tech
Agniva Roy

Stephen Smale’s h-cobordism Theorem was a landmark result in the classification of smooth manifolds. It paved the way towards solutions for the topological Poincaré and Schoenflies conjectures in dimensions greater than 5. Later, building on this, Freedman’s work applied these techniques to 4 manifolds. I shall discuss the ideas relating to h-cobordisms and the proof, which is a wonderful application of handlebody theory and the Whitney trick. Time permitting, we shall explore the world of smooth 4 manifolds further, and talk about cork twists.