Title: Which spheres are groups?
Speaker: Ben Knudsen
The problem of deciding whether a sphere admits a continuous multiplication is a classical problem in topology with important connections to algebra, differential topology, and homotopy theory. After a leisurely tour of the problem and its implications, we'll discuss the ultimately successful reformulation in terms of the Hopf invariant. Examples will be emphasized throughout, and very little background will be assumed.Date: Thursday, March 13, 2014