Develop a principled framework for effective classical–quantum (CQ) field theories

Develop a rigorous theoretical framework for constructing, interpreting, and validating effective classical–quantum (CQ) field theories, including criteria for their domain of validity, treatment of complete positivity and normalization under truncations, and systematic organization of higher-order terms.

Background

The paper argues the presented CQ gravity model should be viewed as an effective field theory and notes that effective CQ theories have not been systematically studied. A principled framework analogous to EFT for unitary QFTs is needed to guide construction, renormalization, and phenomenology of CQ EFTs.

Such a framework would address how to maintain CP and normalization when truncating effective actions, how to organize corrections by energy scales, and how to relate bottom-up CQ EFTs to potential UV completions.