Seminar über Quantenfeldtheorie und Statistische Physik
We revisit the calculation of multi-interval modular Hamiltonians for free fermions using a Euclidean path integral approach. We show how the multi-interval modular flow is obtained by glueing together the single interval modular flows. Our methods are based on a derivation of the non-local field theory describing the reduced density matrix, and makes manifest it's non-local conformal symmetry and $U(1)$ Kacs-Moody symmetry. We will show how the non local conformal symmetry provides a simple calculation of the entanglement entropy. Time-permitting, we will connect multi-interval modular flows to the frame work of extended quantum field theory.