Time: 10:00, Jul. 23, 2025

Location: Rm. 401, Kavli ITS, UCAS

Speaker: Hao Zhang (Kavli IPUM, Univ. of Tokyo)

Abstract:

This talk addresses the question of gauging non-invertible symmetries in 2D CFTs under the formalism of subfactors of von Neumann algebras. He explained it turns out that a fusion category C and a gaugeable algebra object A can be recast in a pair of factors N \subset M. He used this formalism to study the c=1 CFT of SU(2)_1 and gauge various discrete subgroups of the A_4 and A_5 symmetry. This identifies the Brauer-Picard group of the A_4 case, describing all dual theories and their interconnections via gaugings. He also discussed the symmetry enhancement by duality defect in the A_5 case.