Online Talk 

Zoom link: https://princeton.zoom.us/j/96282936122

Passcode: 998749

I will explain a surprising link between diffeomorphism groups of high-dimensional manifolds and mapping class groups of surfaces, which allows one to address two questions about the Torelli group: whether its Lie algebra is stably Koszul, and whether the geometric Johnson homomorphism is stably injective.

This is joint work with Oscar Randal-Williams.