Peter Patzt: Unstable cohomology of SL_n Z and Hopf algebras

Abstract.

The cohomology of \(\mathrm{SL}_n \mathbf{Z}\) has many connections to geometry and number theory and is largely unknown. In this talk, I will give a survey about what is known about it. In particular, I will include newly found unstable classes which come from a Hopf algebra structure. This talk is on joint work with Avner Ash and Jeremy Miller.