We study the symmetry resolved entanglement entropies in one-dimensional systems with boundaries. We provide some general results for conformal invariant theories and then move to a semi-infinite chain of free fermions. We consider both an interval starting from the boundary and away from it. We derive exact formulas for the charged and symmetry resolved entropies based on theorems and conjectures about the spectra of Toeplitz+Hankel matrices. En route to characterise the interval away from the boundary, we prove a general relation between the eigenvalues of Toeplitz+Hankel matrices and block Toeplitz ones. An important aspect is that the saddle-point approximation from charged to symmetry resolved entropies introduces algebraic corrections to the scaling that are much more severe than in systems without boundaries.

我们研究带边界的一维系统的对称解析纠缠熵。我们为共形不变理论提供了一些一般结果，然后转向自由费米子的半无限链。我们既考虑从边界开始又远离边界的间隔。我们基于关于Toeplitz + Hankel矩阵谱的定理和猜想，得出带电对称对称熵的精确公式。在表征远离边界的区间的过程中，我们证明了Toeplitz + Hankel矩阵的特征值与块Toeplitz矩阵的特征值之间的一般关系。一个重要方面是，从带电到对称解析熵的鞍点近似将标度校正引入到标度，比没有边界的系统严厉得多。