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Pseudoisotopies and surfaces in 4-manifolds

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Oliver Singh
Durham University
Mon, 2021-02-01 14:00 - 14:20
Parent event: 
MPIM Topology Seminar

I will talk about pseudo-isotopy, a notion important for understanding self-homeomorphisms (or diffeomorphisms) of manifolds up to isotopy.

Pseudo-isotopies of manifolds in dimensions >=5 were understood in the 70s by work of Cerf for simply connected manifolds, and by Hatcher and Wagoner in the non-simply connected case, using invariants from algebraic K-theory. Quinn later proved Cerf’s result in dimension 4, leading to a classification of self-homeomorphisms of simply connected
 4-manifolds up to isotopy.

 I will talk about my work on what Hatcher and Wagoner’s K-theoretic invariants can say about pseudo-isotopies of non-simply connected 4-manifolds, and explain how these pseudo-isotopies are intimately connected to homotopies of surfaces in 4-manifolds.


Meeting ID: 916 5855 1117
Password: as before.
Contact: Aru Ray and Tobias Barthel.
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