This series consists of talks in the area of Mathematical Physics.
The Alday-Gaiotto-Tachikawa correspondence connects gauge theory on a fourfold with conformal field theory. We are interested in a certain algebro-geometric incarnation of this framework, where the fourfold is an algebraic surface and instantons/differential geometry are replaced with sheaves/algebraic geometry. In this talk, we will present a certain approach to AGT that yields partial results for quite general surfaces, and ask questions about what still needs to be done to state and prove the full correspondence in the language of algebraic geometry.
The localization theorem, which has played a central role in representation theory since its discovery in the 1980s, identifies a regular block of Category O for a semisimple Lie algebra with certain D-modules on its flag variety. In this talk we will explain work in progress which produces a similar picture for the Virasoro algebra and more generally for affine W-algebras.
Quantized lattices, or q-lattices, appear naturally through categorification constructions (for example from zigzag-algebras), but they haven't been studied from a lattice theory point of view. After establishing the necessary background, we'll explain the q-versions of various lattice theory concepts illustrated with examples from combinatorics and graph theory, and we'll list a number of open problems.
Abstract TBA.
In this talk we will discuss three (intimately related) examples of 4-manifold invariants based on higher structures:
- VOA[M4] from transgression of EFTs;
- SW and Donaldson invariants as chiral algebra correlators;
- Massey triple products from trisections.
These topics are based, respectively, on work with A.Gadde, P.Putrov (and work to appear with B.Feigin); recent paper with M.Dedushenko and P.Putrov; and a solo paper of the speaker.
Skew Howe duality is based on a very simple observation: the set of n by m matrices has commuting action of SL_n and SL_m. We can use this observation to study morphisms of GL_m representations using GL_n. This perspective has proven very useful in recent years for studying quantum knot invariants and their categorifications. I will survey work in this direction from the last 10 years, including more recent developments concerning annular skew Howe duality and annular knot invariants.
In this talk, intended for a broader audience, I promise to use techniques only at the level of university calculus. While staying at this level, our goal will be to learn conceptual lessons for categorification of quantum group invariants of knots and 3-manifolds, also known as the Witten-Reshetikhin-Turaev (or WRT) invariants. In particular, we will introduce new q-series invariants of 3-manifolds that have integer powers and integer coefficients and, if time permits, discuss their various constructions and properties. The talk is based on several papers with D. Pei and/or P. Putrov, C.
Abstract TBA
The cobordism hypothesis gives a functorial bijection between oriented
n-dimensional fully local topological field theories, valued in some
higher category C, and the fully dualizable object of C equipped with
the structure of SO(n)-fixed point. In this talk I'll explain recent
works of Haugseng, Johnson-Freyd and Scheimbauer which construct a
Morita 4-category of braided tensor categories, and I'll report on joint
work with Brochier and Snyder which identifies two natural subcategories