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Topology

Upcoming Events

Nov
12
Date4:00 PM
Location
383N
Speaker
Kristen Hendricks, Rutgers University

Abstract

Nov
19
Date4:00 PM
Location
383N
Speaker
Cole Hugelmeyer, Stanford University

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Dec
03
Date4:00 PM
Location
383N
Speaker
Abhishek Mallick, Rutgers University

Abstract

Dec
10
Date4:00 PM
Location
383N
Speaker
Robert Burklund (University of Copenhagen)

Abstract

Jan
07
Date4:00 PM
Location
383N
Speaker
Nathan Geer, Utah State University

Abstract

Jan
14
Date4:00 PM
Location
383N
Speaker
Sungkyung Kang, Oxford University

Abstract

Feb
18
Date4:00 PM
Location
383N
Speaker
Mike Willis, Texas A&M

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Feb
25
Date4:00 PM
Location
383N
Speaker
Sergei Gukov, Caltech

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Past Events

Oct
29
Date4:00 PM
Location
383N
Speaker
Seppo Niemi-Colvin (Indiana University)

Abstract:  I compute the knot Floer complex for the regular fiber of \Sigma(2,3,7), and I show that its Seifert genus and genus in a self homology cobordism agree. The key step in this result was providing upgrades to the surgery formula for knot lattice homotopy. Ozsv\'ath, Stipsicz, and…

Oct
22
Date4:00 PM
Location
383N
Speaker
Ian Zemke (University of Oregon)

Abstract: Satellite operators are a well-trodden subject in Heegaard Floer theory. There are a number of algorithms to compute the effect of satellite operations on knot Floer homology. Most of these go via the bordered theory of Lipshtiz, Ozsvath and Thurston. There are some very helpful…

Oct
15
Date4:00 PM
Location
383N
Speaker
Edgar Bering (San José State University)

Abstract: In general, the classification of finitely generated subgroups of a given group is intractable. Restricting to two-generator subgroups in a geometric setting is an exception. For example, a two-generator subgroup of a right-angled Artin group is either free or free abelian. Jaco and…

Oct
08
Date4:00 PM
Location
383N
Speaker
Melissa Zhang (UC Davis)

Morrison, Walker, and Wedrich’s skein lasagna modules are 4-manifold invariants defined using Khovanov-Rozansky homology similarly to how skein modules for 3-manifolds are defined. In 2020, Manolescu and Neithalath developed a formula for computing this invariant for 2-handlebodies by defining…

Oct
01
Date4:00 PM
Location
383N
Speaker
Kai Nakamura (Stanford)

Abstract: This talk has a simple thesis statement: torus surgeries are a powerful tool to study 4-manifolds, we apply this technology to knot traces. The key insight is that annulus twisting a knot's Dehn surgery can be realized 4-dimensionally as a torus surgery on the knot's trace. We will…

Sep
24
Date4:00 PM
Location
383N
Speaker
Mike Miller Eismeier, University of Vermont

There are now many examples of integer homology spheres which cannot be written as surgery on a knot, but examples which cannot be surgery on some 2-component link have remained out of reach. From one perspective, the difficulty is that the trace of the surgery is an indefinite 4-…

Sep
12
Date4:00 PM
Location
380W
Speaker
Anton Alexeev (University of Geneva)

In this talk, we explain that (infinite dimensional) Teichmueller spaces associated to hyperbolic surfaces with absolute boundary carry Hamiltonian actions of the Virasoro algebra. If time permits, we will also state some open problems for surfaces with marked points. Our study is motivated on…

Jun
11
Date4:00 PM
Location
383N
Speaker
Gary Guth (Stanford)

Work of Hanselman-Rasmussen-Watson has shown that the bordered Floer invariants for a 3-manifold with torus boundary can be represented as a collection of (decorated) immersed curves in the punctured torus; moreover, the Heegaard Floer homology of the closed manifold obtained by gluing two such…

Jun
04
Date4:00 PM
Location
383N
Speaker
David Rose (UNC)

For each compact, orientable surface whose connected components have non-empty boundary, we define a dg category that categorifies the Temperley--Lieb skein of the surface​. In the case when the surface is a disk, our categories are quasi-equivalent to the so-called "Bar-Natan category": the…

May
28
Date4:00 PM
Location
383N
Speaker
Gary Guth (Stanford)

Abstract