On the boundary conformal field theory approach to symmetry-resolved entanglement

We study the symmetry resolution of entanglement entropy an interval in two-dimensional conformal field theories (CFTs), by relating bipartition to geometry annulus with boundary conditions. In presence extended symmetries such as Kac-Moody type current algebrae, is possible only if conditions on preserve part group, i.e. factorization map associated spatial compatible question. The partition function CFT (BCFT) then decomposed terms characters irreducible representations group preserved demonstrate that this decomposition already provides spectrum corresponding bipartition. Considering various same representation, or charge sector, symmetry-resolved Rényi entropies can be derived all orders UV cutoff expansion without need compute charged moments. apply idea theory a free massless boson U(1) U(1) , \mathbb{R} display="inline">ℝ and \mathbb{Z}_2 display="inline">ℤ2 symmetry.