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Geometry and Topology Seminar

Friday, May 6, 2016
3:00pm to 5:00pm
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Unsmoothable group actions on one-manifolds
Thomas Koberda, Mathematics, Univeristy of Virginia,
I will discuss virtual mapping class group actions on compact one-manifolds. The main result will be that there exists no faithful C2 action of a finite index subgroup of the mapping class group on the circle, which generalizes results of Farb-Franks and establishes a higher rank phenomenon for the mapping class group, mirroring a result of Ghys and Burger-Monod. 


For more information, please contact Mathematics Department by email at mathinfo@caltech.edu or visit http://www.math.caltech.edu/~gt/.