Séminaire QUID

Quid of dimension four in topology?

by Anthony Saint-Criq


Dimension four is the pivotal dimension in Topology, where there is enough room for things to get interesting, but not yet enough so that things are very difficult or even do not work at all. We will survey a lot of what goes wrong in this dimension, and why. Non-smoothable manifolds, exotic pairs, classification issues, you name it: it's all a big mess, an 'exotic' mess.