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Abstracts for Conference on "Quantum Topology"

Alternatively have a look at the program.

Knot Invariants from Zero-Dimensional QFT

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Speaker: 
Dror Bar-Natan
Affiliation: 
University of Toronto
Date: 
Mon, 12/05/2025 - 10:00 - 11:00
Location: 
MPIM Lecture Hall

For the purpose of today, an "I-Type Knot Invariant" is a knot invariant computed from a knot diagram by integrating the exponential of a pertubed Gaussian Lagrangian which is a sum over the features of that diagram (crossings, edges, faces) of locally defined quantities, over a product of finite dimensional spaces associated to those same features.

Q. Are there any such things?
A. Yes.

Q. Are they any good?
A. They are the strongest we know per CPU cycle, and are excellent in other ways too.

From quantum topology to topological strings

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Speaker: 
Marcos Marino
Affiliation: 
Université de Genève
Date: 
Mon, 12/05/2025 - 11:30 - 12:30
Location: 
MPIM Lecture Hall

In the last years many interesting connections have been found between quantum invariants of links and three-manifolds, and topological strings on Calabi-Yau threefolds. In this talk I will focus on state integral invariants of hyperbolic knots, their perturbative expansion, and the resurgent structure of the latter.

Rank partition traces and mock Eisenstein series

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Speaker: 
Kathrin Bringmann
Affiliation: 
University of Cologne
Date: 
Mon, 12/05/2025 - 15:00 - 16:00
Location: 
MPIM Lecture Hall

Recently certain traces that are related to quasimodular forms gained attention. These are related to cranks of partitions. Jointly with Pandey and van Ittersum we study partition ranks which are related to mock modular forms.

Skein Algebras and Quantum Groups

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Speaker: 
Thang Le
Affiliation: 
Georgia Institute of Technology
Date: 
Mon, 12/05/2025 - 16:30 - 17:30
Location: 
MPIM Lecture Hall

The $sl_n$-skein algebra of a surface provides a quantization of the $SL_n(\mathbb{C})$ character variety. For surfaces with boundary, this framework extends naturally to the stated skein algebra. We demonstrate how various aspects of quantum groups admit simple and transparent geometric interpretations through the lens of stated skein algebras. In particular, we will present a geometric realization of the dual canonical basis of $\mathcal{O}_q(\mathfrak{sl}_3)$ using skeins.

Braided Hopf structures on exterior algebras

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Speaker: 
Rinat Kashaev
Affiliation: 
Université de Genève
Date: 
Tue, 13/05/2025 - 10:00 - 11:00
Location: 
MPIM Lecture Hall

I will explain how the theory of Nichols algebras allows one to endow the exterior algebra of a vector space of dimension greater than one with a one-parameter family of braided Hopf algebra structures. The structure constants with respect to a natural set-theoretic basis can be explicitly computed, although determining the braiding structure in explicit terms is rather challenging. There exists a one-parameter family of diagonal automorphisms, which make it possible to construct solutions to the (constant) Yang--Baxter equation.

Skein modules, character varieties and essential surfaces of 3-manifolds

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Speaker: 
Efstratia Kalfagianni
Affiliation: 
Michigan State University
Date: 
Tue, 13/05/2025 - 11:30 - 12:30
Location: 
MPIM Lecture Hall

The $SL_2(C)$-skein modules of closed 3-manifolds were defined by in the 90’s but till recently little was known about their structure. The modules depend on a parameter A and can be considered over $ {\mathbb Z}[A^{\pm 1}]$ or over ${\mathbb Q}(A)$.

The ${\mathbb Q}(A)$-module is known to be finitely generated  while the structure over ${\mathbb Z}[A^{\pm 1}]$ can be complicated.

Topological applications of twisted Drinfeld doubles

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Speaker: 
Roland van der Veen
Affiliation: 
University of Groningen
Date: 
Tue, 13/05/2025 - 15:00 - 16:00
Location: 
MPIM Lecture Hall

A handout for this talk will be available at https://www.rolandvdv.nl/Talks/Stavros25/.
In joint work with Daniel Lopez Neumann we showed how the quantum invariants arising from the twisted double yield a lower bound for the knot genus. We will give an elementary sketch of the construction and discuss further applications.

 

On Matveev-Piergallini moves for branched spines

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Speaker: 
Sakie Suzuki
Affiliation: 
Institute of Science Tokyo
Date: 
Tue, 13/05/2025 - 16:30 - 17:30
Location: 
MPIM Lecture Hall

The Matveev-Piergallini (MP) moves on spines of 3-manifolds are well-known for their correspondence with the Pachner 2-3 moves in dual ideal triangulations. Benedetti and Petronio introduced combinatorial descriptions of closed 3-manifolds and combed 3-manifolds using branched spines and their equivalence relations, which involve MP moves with 16 distinct branching patterns. In this talk, I will demonstrate that these 16 MP moves on branched spines are derived from a primary MP move, pure sliding moves, and their inverses.

Symplectic Invariants on Calabi-Yau 3 folds, Modularity and Stability

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Speaker: 
Albrecht Klemm
Affiliation: 
University of Bonn / University of Sheffield
Date: 
Wed, 14/05/2025 - 10:00 - 11:00
Location: 
MPIM Lecture Hall

We discuss techniques to calculate symplectic invariants on CY 3-folds $M$, namely Gromov-Witten (GW) invariants, Pandharipande-Thomas (PT) invariants, and Donaldson-Thomas (DT)  invariants.

Representation theory for line operators

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Speaker: 
Tudor Dimofte
Affiliation: 
University of Edinburgh
Date: 
Wed, 14/05/2025 - 11:30 - 12:30
Location: 
MPIM Lecture Hall

Work that started nearly 20 years ago, involving complex Chern-Simons theory, ideal triangulations and my first collaborations with Stavros, has brought me recently to ask increasingly general questions about extended operators (the things that form knots or other interesting topological/geometric structures) in quantum field theory. In particular, can line operators in a QFT always be described as modules for a quantum-group-like algebra? And, if so, where (physically) does the "quantum group" actually appear in the QFT?

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