Quantum Entanglement on Boundaries

Abstract: Quantum entanglement in 3 spatial dimensions is studied in systems with physical boundaries when an entangling surface intersects the boundary. We show that there are universal logarithmic boundary terms in the entanglement R\'{e}nyi entropy and derive them for different conformal field theories and geometrical configurations. The paper covers such topics as spectral geometry on manifolds with conical singularities crossing the boundaries, the dependence of the entanglement entropy on mutual position of the boundary and the entangling surface, effects of acceleration and rotation of the boundary, relations of coefficients in the trace anomaly to coefficients in the boundary logarithmic terms in the entropy. The computations are done for scalar, spinor and gauge fields.