Symmetry breaking boundaries I. General theory
arXiv:hep-th/9902132 · doi:10.1016/S0550-3213(99)00406-X
Abstract
We study conformally invariant boundary conditions that break part of the bulk symmetries. A general theory is developped for those boundary conditions for which the preserved subalgebra is the fixed algebra under an abelian orbifold group. We explicitly construct the boundary states and reflection coefficients as well as the annulus amplitudes. Integrality of the annulus coefficients is proven in full generality.
60 pages, LaTeX2e; typos fixed and other minor corrections