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Junior Topology
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Max Riestenberg, Zoom (see email): The space of closed subgroups of R^2
Wednesday, January 27, 2021, 02:00pm - 03:00pm
The set of closed subgroups of a topological group has a natural topology called the Chabauty topology. The topology of the space of closed subgroups of R^2 was described by Pourezza and Hubbard in 1978. It turns out to be homeomorphic to S^4, and the complement of the lattices turns out to be the suspension of the trefoil knot. I will sketch their proof, which relies on the famous Weierstrass formula
Location: Zoom (see email)

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