PhD Thesis Defence

Wednesday, July 31, 2024 5:00 pm - 6:30 pm EDT (GMT -04:00)

Aiden Suter, Department of Pure Mathematics, University of Waterloo 

“Mathematical aspects of Higgs and Coulomb branches” 

3d mirror symmetry is a duality between topological twists of 3 dimensional quantum field theories (QFTs) with N=4 supersymmetry. One of the most salient features of this duality is the symplectic duality between the branches of the moduli space of vacua of the full physical theory know as the “Higgs” and “Coulomb” branches. These branches are singular hyperkahler varieties that are interchanged under the duality. In this talk, I will primarily discuss two results regarding these varieties:

The first utilises a construction due to Costello and Gaiotto allowing one to associate a vertex operator algebra (VOA) to certain boundary conditions of these twisted QFTs and it has been conjectured that the associated variety of this VOA is the Higgs branch of the theory. In this talk I will outline a proof of this conjecture in the case of U(1) gauge theory acting on n>3 hypermultiplets, building on prior work of Beam and Ferrari who conjectured that the boundary VOA is the simple quotient of the psl(n|n) affine VOA.

In the second part of this talk I will outline a construction of a tilting generator for the derived category of sheaves on T*Gr(2,4). This space is the Coulomb branch for a certain quiver gauge theory and the construction is a realisation of a result due to Webster who proved the existence of such a tilting generator. In the case of quiver gauge theories such as this, the Coulomb branch algebra can be described in terms of a cyldrinical KLRW algebra, a type of diagrammatic algebra. Using these diagrammatic methods we explicitly describe the tilting generator and find that it differs to those previously known in the literature.

Remote - contact Ben Webster for the Zoom link.