Topology in Dimension 4.5
October 31–November 4, 2022 at the Banff International Research Station
This conference brought together experts in various aspects of four-dimensional topology. Themes included isotopy and concordance of surfaces in 4-manifolds and diffeomorphism groups of 4-manifolds.
The organizers of this conference were David Gay, Jason Joseph, Maggie Miller, and Hannah Schwartz.
Several participants kindly shared their notes prepared for the expository mini-series talks (either their research notes or talk slides).
Ryan Budney — Diffeomorphism groups of 4-manifolds (motivation and background)
Ryan Budney — Diffeomorphism groups of 4-manifolds (recent results)
Ryan Budney — How to show a barbell diffeomorphism is nontrivial (research talk)
Anthony Conway — Invariant of 2-knots (notes)
David Gabai — Dax's work on embedding spaces
Mark Powell — Concordance and isotopy invariants of surfaces (notes)
Rob Schneiderman — Three views of the Freedman–Quinn invariant
Peter Teichner — Isotopy classification of half-disks in 4-manifolds (research talk)
