For each finite index subgroup \(H\) of the mapping class group of a closed hyperbolic surface, and for each real number \(r>1\) we prove that there does not exist a faithful \(C^r\)-action (in Hölder's sense) of \(H\) on a circle. For this, we determine the allowed regularities of faithful actions by many right-angled Artin groups on a circle. (Joint with Thomas Koberda and Cristobal Rivas)
This will be a hybrid seminar. The live speaker in SR10 will also be streamed on Zoom.
Join Zoom meeting ID 613 8691 2732 or via the link below.
Passcode: A group is called an ________ group if it admits an invariant mean. (8 letters, lowercase)