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Geometry & Topology Seminar | Tyrone Ghaswala (University of Waterloo)
	
 Nov 27, 2025 
 3:30PM to 4:30PM





	





























Date/Time

Date(s) - 27/11/2025
3:30 pm - 4:30 pm





Speaker: Tyrone Ghaswala (University of Waterloo)


Location: Hamilton Hall, Room 312


Title: Big mapping class groups and uniqueness of Polish structures


Abstract: Suppose you are given a topological group. You may wonder about how much the group structure determines the topology. At first glance, the answer appears to be “not very much at all”, since every topological group admits the discrete topology, and the trivial topology, both of which are compatible with the group operation.


Mapping class groups of infinite-type surfaces are humungous (not a technical term), and come equipped with a Polish topology. We can ask a refinement of the above question: How much does the group structure of a mapping class group determine its Polish topology? In this talk we’ll investigate this question, leading to a perhaps surprising answer.


This is joint work with Sumun Iyer, Robbie Lyman, and Nick Vlamis.