Würzburg Seminar on Quantum Field Theory and Gravity

I will make two, maybe three, observations on entanglement in quantum field theory.  1) In 3-dimensional gauge theories, part of the entanglement, the so-called contact term, can be related to the BFK surgery formula for the determinant of the Laplacian on Riemannian manifolds. 2) Calculation of entanglement by direct integration of wave functionals leads to a nuts-and-bolts version of the Reeh-Schlieder theorem and can be generalized to analyze the role of interface boundary conditions. 3) If time permits, I may briefly discuss how entanglement for a noncommutative space can be related to a Chern-Simons action for the spin connection in its commutative limit.