Our seminar meets Tuesdays at 4:30 in JCC 502. Talks are in person and also streamed on Zoom. You can subscribe to the GGTT mailing list at https://elist.tufts.edu/sympa/info/ggtt for details and announcements. The seminar organizers are Corey Bregman, Nima Hoda, Kim Ruane and Genevieve Walsh.
| Date | Name | Title | ||
|---|---|---|---|---|
| Sept 10 | Corey Bregman (Tufts) | Cannon's conjecture for cubulated hyperbolic groups Abstract: We show that cubulated hyperbolic groups with spherical boundary of dimension 3 or at least 5 are virtually fundamental groups of closed, orientable, aspherical manifolds, provided that there are sufficiently many quasi-convex, codimension-1 subgroups whose limit sets are locally flat subspheres. The proof is based on ideas used by Markovic in his work on Cannon’s conjecture for cubulated hyperbolic groups with 2-sphere boundary. This is joint work with M. Incerti-Medici. | ||
| Sept 17 | Trent Lucas (Brown) | Mapping class groups of 3-manifolds and branched covers Abstract: Given a branched cover of manifolds, one can lift homeomorphisms along the cover to obtain a (virtual) homomorphism of mapping class groups. An important theorem of Birman-Hilden and MacLachlan-Harvey says that this lifting map is injective for most finite regular branched covers of surfaces. Margalit-Winarski asked whether one could prove an analogous result for 3-manifolds. In this talk, we answer this question by showing that in contrast to the surface case, the lifting map is not injective for most branched covers of 3-manifolds. This includes double covers of S^3 branched over an unlink, which generalize the hyperelliptic branched covers of S^2; for these covers, we describe the kernel of the lifting map. In these examples, the lifting map is closely related to a natural map between symmetric automorphism groups of free products. | ||
| Sept 24 | Thomas Ng (Brandeis) | TBA Abstract: | ||
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| Oct 29 | Rachael Boyd (University of Glasgow) | Abstract: | ||
| Nov 5 | No Seminar | Election Day | ||
| Nov 12 | No Seminar | Monday schedule on Tuesday | ||
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