Light-ray moments as endpoint contributions to modular Hamiltonians
ABSTRACT :
We consider excited states in a CFT, obtained by applying a weak unitary perturbation to the vacuum. The perturbation is generated by the integral of a local operator of modular weight over a spacelike surface passing through x = 0. For n geq 2, the modular Hamiltonian associated with a division of space at x =0 picks up an endpoint contribution, sensitive to the details of the perturbation at x=0. The endpoint contribution is a sum of light-ray moments of the perturbing operator J^{(n)} and its descendants. For perturbations on null planes only moments of J^{(n)} itself contribute. Work based on https://arxiv.org/abs/2006.13317https://arxiv.org/abs/2103.08636.
This talk is a part of the activities of the Center for Quantum Information Theory of Matter and Spacetime of IIT Madras