Pure Math Colloquium

Monday, November 10, 2025 2:30 pm - 3:30 pm EST (GMT -05:00)

Patrick Naylor, McMaster University

Doubling Gluck twists

The Gluck twist of an embedded 2-sphere in the 4-sphere is a 4-manifold that is homeomorphic but not obviously diffeomorphic to the 4-sphere. Despite considerable study, these strange manifolds have remained a long-standing source of potential counterexamples to the only remaining case of the Poincaré conjecture. In this talk, I will give an overview of this conjecture, a visual introduction to 2-dimensional knot theory, and describe conditions that guarantee that (some) Gluck twists are standard, i.e., diffeomorphic to the 4-sphere. This is based on joint work with Dave Gabai and Hannah Schwartz.

MC 5501