Speaker
Dr
Quentin Faes
(Tokyo)
Description
The Johnson homomorphisms encode the action of the mapping class group on the nilpotent quotients of the fundamental group of the surface, embedding the graded space associated with the Johnson filtration in some Lie algebra of derivations. In this talk, we will use the infinitesimal Dehn-Nielsen representation of the mapping class group to study torsion in the cokernel of the Johnson homomorphisms.
