42nd Workshop in Geometric Topology 2025
Embedded Files
at Oberlin College
June 12–14, 2025
Oberlin College is hosting the 42nd Annual Workshop in Geometric Topology 2025 from June 12 to June 14
The workshop programming begins at 9:00 a.m. on Thursday, June 12, and ends at noon on Saturday, June 14. Each day there will be a one-hour lecture by Principal Speaker Danny Calegari as well as contributed talks by participants. The program is designed so there will be ample time for informal networking among participants. The workshop ends on Saturday with a problem session. For those staying until Sunday, we will visit the Cuyahoga Valley National Park on Saturday afternoon followed by dinner.
Principal Speaker: Danny Calegari
Principal Speaker Danny Calegari of the University of Chicago will give three, one-hour talks on zippers, universal circles, and the unification of dynamical and geometric perspectives of 3-manifold topology.
Abstract: If M is a hyperbolic 3-manifold fibering over the circle, then the fundamental group of M acts faithfully by homeomorphisms on a circle—the circle at infinity of the universal cover of the fiber—preserving a pair of invariant (stable and unstable) laminations. Many different kinds of dynamical structures including taut foliations and quasigeodesic or pseudo-Anosov flows are known to give rise to universal circles—a circle with a faithful action of the fundamental group preserving a pair of invariant laminations—and those universal circles play a key role in relating the dynamical structure to the geometry of M. In these lectures, I will introduce the idea of *zippers*, which give a new and direct way to construct universal circles, streamlining the known constructions in many cases, and giving a host of new constructions in others. In particular, zippers—and their associated universal circles—may be constructed directly from homological objects (uniform quasimorphisms), causal structures (uniform left orders), and many other structures.
Contributed Talks
Contributed Talks
Participants are invited to contribute talks. Time will be allotted each day for 20-minute talks by participants. Abstracts may be entered on the registration form below.
Financial Support
Financial Support
The 42nd Annual Workshop in Geometric Topology is supported by the National Science Foundation grant no. 2350374. Contingent on that grant not being frozen, financial support may be available to cover partial travel and living expenses of participants who do not have other funding for their research. Such support can be requested on the registration form below. To receive full consideration, requests for support should be submitted by April 20, 2025. Graduate students and recent PhDs in geometric topology are especially encouraged to apply.
Deadlines
Deadlines
Requests for Financial Support: April 20, 2025 (deadline passed)
Requests for Contributed Talks: May 20, 2025
Registration
Registration
To register without financial support from the workshop, email Jack Calcut at the address below.
Poster
Poster
Download a poster for WGT 2025.
Organizers
Organizers
Fredric Ancel, University of Wisconsin-Milwaukee
Jack Calcut, Oberlin College
Greg Friedman, Texas Christian University
Craig Guilbault, University of Wisconsin-Milwaukee
Molly Moran, Colorado College
Nathan Sunukjian, Calvin University
Local Contact
Local Contact
Contact Jack Calcut (jcalcut@oberlin.edu) if you have questions about the workshop.
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