Quantum general covariance
Christian Gaß, José M. Gracia-Bondía, Karl-Henning Rehren
April 12, 2023
The structure of quantum interactions with fields of helicity two
("gravitons") is strongly constrained by three principles: positivity (Hilbert
space), covariance, and locality of observables. To fulfil them simultaneously,
one needs to work with string-localized fields. The results then follow from
the condition that entities closely related to observables, like the S-matrix,
be local and string-independent. They in particular reproduce the interactions
dictated by general covariance in classical field theory. Graviton-matter
couplings are consistent only when the graviton self-interaction is taken into
account as well.
Keywords:
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