Ising BCFT from Fuzzy Hemisphere

Abstract

We extend the recently introduced fuzzy sphere technique for the 3d Ising CFT to the case of boundary CFT (BCFT) using the fuzzy hemisphere. This allows to study conformal boundary conditions, and we investigate the three boundary universality classes of the 3d Ising CFT. These include the ordinary, extraordinary, and special boundary conditions. We identify the qualitative signatures of boundary conformal invariance, and in the cases of ordinary and extraordinary boundary conditions, obtain numerical estimates for the spectrum of low-lying boundary primaries. For the special boundary conditions, we are only able to see their qualitative features, while reliable estimates of the scaling dimensions of boundary primaries are left for the future work.