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 J(n) of modular weight n over a spacelike surface passing through x = 0. For |n| ≥ 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 (including the shape of the spacelike surface) 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.
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ArXiv ePrint: 2103.08636
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Kabat, D., Lifschyt, G., Nguyen, P. et al. Light-ray moments as endpoint contributions to modular Hamiltonians. J. High Energ. Phys. 2021, 74 (2021). https://doi.org/10.1007/JHEP09(2021)074
- Conformal Field Theory
- Field Theories in Higher Dimensions
- Field Theories in Lower Dimensions