Seminar meets Tuesdays at 4:30 in BP 101 in the Tufts Math Department. You can subscribe to the GGTT mailing list here. In Fall 2018, the seminar organizers are Robert Kropholler, Kim Ruane and Genevieve Walsh.

 

Date Name Title
Sep 11 Oliver Wang Cohomology of relatively hyperbolic groups
Abstract: Bestvina and Mess have shown that the group cohomology of a hyperbolic group is isomorphic to the Cech cohomology of the group’s boundary. To achieve this, they show that both cohomology groups are isomorphic to the compactly supported cohomology of the Rips complex. I will discuss recent work with Jason Manning, in which the cohomology of a relatively hyperbolic group pair is shown to be isomorphic to the Cech cohomology of the Bowditch
boundary. If there is time, I will also discuss some corollaries.
Sep 18 Peter Kropholler Amenability and rank conditions on group rings
Abstract: We’ll explain how Bartholdi and Kielak’s work on cellular automata can be used to show that the integral group ring of a group G satisfies the strong rank condition if and only if G is amenable. This in turn can be used to prove a conjecture of Wolfgang Lueck on dimension flatness for L^2 cohomology. In addition, the results imply that the group ring \mathbb{Z}G can be Noetherian only if the group is amenable with max on subgroups. At present the only known such groups are polycyclic by finite.
Sep 25 Siddhi Krishna Taut Foliations, Positive 3-Braids, and the L-Space Conjecture
Abstract: The L-Space Conjecture is taking the low-dimensional topology community by storm. It aims to relate seemingly distinct Floer homological, algebraic, and geometric properties of a closed 3-manifold Y. In particular, it predicts a 3-manifold Y isn’t “simple” from the perspective of Heegaard-Floer homology if and only if Y admits a taut foliation. The reverse implication was proved by Ozsvath and Szabo. In this talk, we’ll present a new theorem supporting the forward implication. Namely, we’ll discuss how to build taut foliations for manifolds obtained by surgery on positive 3-braid closures. No background in Heegaard-Floer or foliation theories will be assumed.
Oct 2 James Farre TBA
Abstract: TBA
Oct 9 No Seminar No Seminar
Oct 16 Daniel Woodhouse TBA
Abstract: TBA
Oct 16 Emily Stark TBA
Abstract: TBA
Oct 23 TBA
Abstract: TBA
Oct 30 Thomas Koberda TBA
Abstract: TBA
Nov 6 Yulan Qing TBA
Abstract: TBA
Nov 13 TBA
Abstract: TBA
Nov 20 Valentina Disarlo TBA
Abstract: TBA
Nov 27 TBA
Abstract: TBA
Dec 4 TBA
Abstract:TBA
Dec 11 Jen Taback and Rob Kropholler TBA
Abstract:TBA