The derivative map for diffeomorphism of disks: An example

Diarmuid Crowley, Thomas Schick, Wolfgang Steimle

We prove that the derivative map $d:{\mathrm{Diff}}_{\partial }(D^k)\to {\Omega }^{k}S{O}_k$, defined by taking the derivative of a diffeomorphism, can induce a nontrivial map on homotopy g…