Calendar

In this talk, we construct a dgBV algebra PV*(X) associated to a possibly degenerate Calabi–Yau variety X equipped with local thickening data. This gives a version of the Kodaira–Spencer dgLa which is applicable to degenerated spaces including both log smooth or maximally degenerated Calabi–Yau. We use this to prove an unobstructedness result about the smoothing of degenerated Log Calabi–Yau varieties X satisfying Hodge–deRham degeneracy property for cohomology of X, in the spirit of Kontsevich–Katzarkov–Pantev. This is a joint work with Kwokwai Chan and Naichung Conan Leung.

Zoom: https://harvard.zoom.us/j/94717938264

Quantum Fourier analysis is a subject that combines an algebraic Fourier transform (pictorial in the case of subfactor theory and topological quantum field theory) with analytic estimates. We give an overview of quantum Fourier analysis in this talk. We highlight an application in recent work joint with Sebastien Palcoux and Jinsong Wu: we find new, surprisingly efficient, analytic obstructions of unitary categorification of fusion rings by applying quantum Fourier analysis to the Drinfeld center of unitary fusion categories.

Zoom: https://harvard.zoom.us/j/779283357

Yang-Mills theory. In my talk I will tell how to derive a holomorphic
anomaly equation for its partition function on CP^2 by two different,
but somewhat analogous, methods. First is the derivation from the path
integral of the effective theory on the Coulomb branch. The second is
the derivation from the path-integral in the effective 2d theory
obtained by compactification of the corresponding 6d (2,0) theory on the
ternsor branch.

Zoom : https://harvard.zoom.us/j/977347126

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“Type-II” fracton phases are exotic, gapped phases of matter in which all point-like excitations are deconfined but completely immobile. We present two approaches to constructing and analyzing models for type-II fractons using tools from conventional topological order. First, we use networks of defects in topological quantum field theories to describe Haah’s B code, which is a type-II fracton model. We use this fact as evidence for a conjecture that all fracton models can be described by a suitable defect network. Second, we show how gauging global symmetries of Abelian type-II fracton models produces new, exactly solvable models with non-Abelian type-II fractons, and we analyze the unusual excitations.

Zoom: https://harvard.zoom.us/j/977347126