The UC Berkeley Representation theory and tensor categories seminar
Spring 2025 - Tuesday 2:10pm - 3:30pm, Evans 939
Organizers: Vera Serganova, Ilia Nekrasov, and Alexandra Utiralova

If you would like to be added to the seminar mailing list, contact any of the organizers.

DATE SPEAKER TITLE (click to show abstract)
January 21 Nicolai Reshetikhin , UC Berkeley and BIMSA
Invariants of tangles with a flat connection in the complement I. Abstract: The construction of these invariants based on properties of quantum groups at roots of unity and it was proposed in a joint work with R. Kashaev. It is related to homotopy quantum field theory by V. Turaev. In this talk, I will recall the construction of these invariants, and I will explain why Poisson structures on the center of quantum groups at a root of unity that appear are natural from the geometry of flat connections in the complement to a tangle.
January 28 No seminar
February 4 Nicolai Reshetikhin , UC Berkeley and BIMSA
Invariants of tangles with a flat connection in the complement II.

Continuation of the previous talk.

Abstract: The construction of these invariants based on properties of quantum groups at roots of unity and it was proposed in a joint work with R. Kashaev. It is related to homotopy quantum field theory by V. Turaev. In this talk, I will recall the construction of these invariants, and I will explain why Poisson structures on the center of quantum groups at a root of unity that appear are natural from the geometry of flat connections in the complement to a tangle.

February 11 Christian Gaetz, UC Berkeley
SL(n) web bases from hourglass plabic graphs Abstract: The SL(3) web basis is a special diagrammatic basis for certain spaces of tensor invariants developed in the late 90’s by Kuperberg as a tool for computing quantum link invariants. Since then this basis has found connections and applications to cluster algebras, dimer models, quantum topology, and tableau combinatorics. A main open problem has remained: how to find a basis replicating the desirable properties of this basis for SL(4) and beyond? I will describe joint work with Oliver Pechenik, Stephan Pfannerer, Jessica Striker, and Josh Swanson in which we construct such a basis for SL(4). Modified versions of plabic graphs and the six-vertex model and new tableau combinatorics will appear along the way.
February 18
February 25
March 4 Dmytro Matvieievskyi, Kavli IMPU
March 11
March 18
March 25 Spring Recess
April 1
April 8
April 15
April 22 Agustina Czenky, USC
April 29
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