# Derek Krepski

## The Hopf Invariant

Date Monday, March 17, 2014

This talk will introduce the Hopf invariant, a classical topic in algebraic topology/homotopy theory, and discuss its relation to the non-existence of bilinear multiplications on $R^n$ (without zero divisors) for $n$ other than 1, 2, 4 and 8 (where of course such multiplications exist, in the real numbers, complex numbers, quaternions and octonians, respectively).