Mapping class groups of 4-manifolds via the Budney-Gabai invariants
Weizhe Niu (University of Glasgow)
Monday 20th May 16:00-17:00 Maths 311B
Abstract
According to the work of Budney-Gabai, the smooth mapping class group of S1 × D3 is infinitely generated. Their construction is based on a special class of diffeomorphisms known as barbell diffeomorphisms. They use a rational homotopy invariant to detect an infinite sequence of linearly independent generators, represented by certain barbell diffeomorphisms. In this talk, I will review their construction and discuss some extensions of their results. I will also discuss an adaptation of their approach to the mapping class group of the boundary-connected sums of S1 × D3s.
Add to your calendar
Download event information as iCalendar file (only this event)