MS Seminar (Mathematics - String Theory)

Speaker: Yunqin Zheng (KITS-UCAS)
Title: On the absence of simple, symmetric, conformal boundary conditions
Date (JST): Tue, Dec 23, 2025, 13:30 - 15:00
Place: Seminar Room A
Abstract:
There is a common lore that given a CFT with symmetry described by a fusion category C, when C is anomaly free, there exists a simple conformal boundary condition of the CFT preserving C. Recently, several examples were recognized to violate this lore, including compact boson with Z_p x Z_q symmetry and tetra critical Ising model with Rep(S3) symmetry. I will propose a criterion explaining why such simple symmetric conformal boundary conditions are absent in these CFTs, and test a few other new examples.