Organiser: Sven Möller
| Room | Day | Time | Speaker | Title | Abstract |
|---|---|---|---|---|---|
| Geom. 414 | 23/05/2025 | 11:00-12:00 | Rızacan Çiloğlu (Technische Universität Darmstadt) | Bezrukavnikov's equivalence for non-split reductive groups | For a split reductive group, Arkhipov-Bezrukavnikov have proven an equivalence of categories between Iwahori-Whittaker sheaves on the affine flag variety and coherent sheaves on the Springer resolution of its Langlands dual group. In this talk, I will discuss the extension of this equivalence to possibly non-split reductive groups, and work in progress aiming to extend Bezrukavnikov's equivalence to such groups. |
| Geom. 414 | 25/04/2025 | 14:45-15:30 | Yuto Moriwaki (RIKEN, Japan) | Cohomology ring of unitary N=(2,2) full vertex algebra and mirror symmetry | |
| Geom. 428 | 17/12/2024 | 14:15-15:00 | Thomas Creutzig (Friedrich-Alexander-Universität Erlangen-Nürnberg) | From TQFT to the Waarnar-Zudilin conjecture | Three-dimensional topological quantum field theories often admit chiral boundary conditions that support a vertex operator algebra. I will discuss a two-parameter family of VOAs that supposedly arises in this way. The best check of the proposal is the verification of character identities, which in this instance coincides with a conjecture by Waarnar and Zudilin. |
| Geom. 428 | 17/12/2024 | 15:00-15:45 | Brandon Rayhaun (Yang Institute for Theoretical Physics, Stony Brook, USA) | Equivalence relations on vertex operator algebras | Inspired by results in the theory of integral lattices and the theory of tensor categories, I will describe an interconnected web of equivalence relations on (suitably regular) vertex operator algebras, and discuss some applications thereof. |
| Sedanstr. 19, 221 | 05/12/2024 | 14:15-15:00 | Thibault Juillard (Laboratoire de Mathématiques d'Orsay, France) | Reduction by stages for affine W-algebras, a geometric approach | Affine W-algebras form a family of vertex algebras indexed by the nilpotent orbits of a simple finite dimensional complex Lie algebra. Each of them is built as a noncommutative Hamiltonian reduction of the corresponding affine Kac-Moody algebra. In this talk, I will present a joint work with Naoki Genra about the problem of reduction by stages for these affine W-algebras: given a suitable pair of nilpotent orbits in the simple Lie algebra, it is possible to reconstruct one of the two affine W-algebras associated to these orbits as the Hamiltonian reduction of the other one. I will insist on how this problem uses our previous work about reduction by stages between Slodowy slices, which are Poisson varieties associated with affine W-algebras. I will also mention some applications and motivations coming from Kraft-Procesi rule for nilpotent Slodowy slices, and isomorphisms between simple affine admissible W-algebras. |
| Geom. 428 | 14/11/2023 | 14:15-15:00 | Hannes Knötzele (Universität Hamburg) | Towards cyclic orbifolds of rational vertex operator algebras | For a holomorphic vertex operator algebra (VOA) V with a finite cyclic group G of automorphisms, the category of modules of the fixed point vertex operator subalgebra V^G is equivalent to the module category of a twisted Drinfeld double of G. For a rational but not necessarily holomorphic VOA V, a general description of the category of modules of V^G is unknown. In this talk, I will sketch the main difficulties facing this problem. First, I will recall categorical prerequisites like equivariantisation and crossed modular categories. Then, I will apply these ideas to examples that generalise Tambara-Yamagami categories. |
| Geom. 435 | 06/07/2023 | 14:15-15:45 | Dražen Adamović (University of Zagreb, Croatia) | On weight and logarithmic modules for some affine W-algebras | |
| Geom. 435 | 06/07/2022 | 14:15-15:45 | Yuto Moriwaki (RIMS, Kyoto University, Japan) | Non-chiral conformal field theory and vertex algebra | |
| Geom. 435 | 28/06/2022 | 14:15-15:00 | Hiroshi Yamauchi (Tokyo Woman's Christian University, Japan) | An exceptional construction of the moonshine VOA |