- Open Access
Diffeomorphism invariance of the effective gravitational action
Phys. Rev. D 112, 045002 – Published 5 August, 2025
DOI: https://doi.org/10.1103/p2cz-qwnm
Abstract
We investigate on the diffeomorphism invariance of the effective gravitational action, focusing in particular on the path integral measure. In the literature, two different measures are mainly considered, the Fradkin-Vilkovisky and the Fujikawa one. With the help of detailed calculations, we show that, despite claims to the contrary, the Fradkin-Vilkovisky measure is diffeomorphism invariant, while the Fujikawa measure is not. In particular, we see that, contrary to naïve expectations, the presence of factors in the Fradkin-Vilkovisky measure is necessary to ensure the invariance of the effective gravitational action. We also comment on results recently appeared in the literature, and show that formal calculations can easily miss delicate points.
Physics Subject Headings (PhySH)
Article Text
References (29)
- S. Weinberg, What is quantum field theory, and what did we think it is?, Proceedings of the Conference: “Historical Examination and Philosophical Reflections on the Foundations of Quantum Field Theory,” Boston (1996), p. 241, arXiv:hep-th/9702027.
- C. Branchina, V. Branchina, F. Contino, and A. Pernace, Path integral measure and the cosmological constant, Phys. Rev. D 111, 105018 (2025).
- C. Branchina, V. Branchina, F. Contino, and A. Pernace, Path integral measure and RG equations for gravity, Phys. Rev. D 111, 125021 (2025).
- C. Branchina, V. Branchina, F. Contino, and N. Darvishi, Dimensional regularization, Wilsonian RG, and the naturalness and hierarchy problem, Phys. Rev. D 106, 065007 (2022).
- C. Branchina, V. Branchina, and F. Contino, Physical tuning and naturalness, Phys. Rev. D 107, 096012 (2023).
- C. Branchina, V. Branchina, and F. Contino, Naturalness and UV sensitivity in Kaluza-Klein theories, Phys. Rev. D 108, 045007 (2023).
- C. Branchina, V. Branchina, F. Contino, and A. Pernace, Does the cosmological constant really indicate the existence of a dark dimension?, Int. J. Geom. Methods Mod. Phys. 22, 2450305 (2025).
- C. Branchina, V. Branchina, F. Contino, and A. Pernace, Dark dimension and the effective field theory limit, Int. J. Geom. Methods Mod. Phys. 22, 2450303 (2025).
- M. Reuter, Nonperturbative evolution equation for quantum gravity, Phys. Rev. D 57, 971 (1998).
- W. Souma, Nontrivial ultraviolet fixed point in quantum gravity, Prog. Theor. Phys. 102, 181 (1999).
- M. Reuter and F. Saueressig, Renormalization group flow of quantum gravity in the Einstein-Hilbert truncation, Phys. Rev. D 65, 065016 (2002).
- A. Bonanno and M. Reuter, Proper time flow equation for gravity, J. High Energy Phys. 02 (2005) 035.
- E. S. Fradkin and G. A. Vilkovisky, S matrix for gravitational field. II. Local measure, general relations, elements of renormalization theory, Phys. Rev. D 8, 4241 (1973).
- E. S. Fradkin and G. A. Vilkovisky, Unitarity of S matrix in gravidynamics and general covariance in quantum domain, Lett. Nuovo Cimento 13, 187 (1975).
- E. S. Fradkin and G. A. Vilkovisky, Quantization of relativistic systems with constraints: Equivalence of canonical and covariant formalisms in quantum theory of gravitational field, Report No. CERN-TH-2332.
- K. Fujikawa, Path integral measure for gravitational interactions, Nucl. Phys. B226, 437 (1983).
- A. Bonanno, K. Falls, and R. Ferrero, Path integral measures and diffeomorphism invariance, J. High Energy Phys. 05 (2025) 164.
- S. D. Odintsov, Renormalization group, effective action, and grand unification theories in curved space-time, Fortschr. Phys. 39, 621 (1991).
- A. A. Bytsenko, S. D. Odintsov, and S. Zerbini, The effective action in gauged supergravity on hyperbolic background and induced cosmological constant, Phys. Lett. B 336, 355 (1994).
- I. L. Buchbinder, S. D. Odintsov, and I. L. Shapiro, Effective Action in Quantum Gravity (Routledge, New York, 2017).
- D. J. Toms, The functional measure for quantum field theory in curved space-time, Phys. Rev. D 35, 3796 (1987).
- H. Leutwyler, Gravitational field: Equivalence of Feynman quantization and canonical quantization, Phys. Rev. 134, B1155 (1964).
- I. L. Buchbinder and S. L. Lyakhovich, Canonical quantization and local measure of gravity, Classical Quantum Gravity 4, 1487 (1987).
- E. S. Fradkin and G. A. Vilkovisky, On renormalization of quantum field theory in curved space-time, Lett. Nuovo Cimento 19, 47 (1977).
- A. O. Barvinsky and G. A. Vilkovisky, The generalized Schwinger-Dewitt technique in gauge theories and quantum gravity, Phys. Rep. 119, 1 (1985).
- C. Branchina, V. Branchina, F. Contino, R. Gandolfo, and A. Pernace, On the RG flow of the Newton and cosmological constant, arXiv:2505.07628.
- A. Held, B. Knorr, J. M. Pawlowski, A. Platania, M. Reichert, F. Saueressig, and M. Schiffer, Comment on Path integral measure and RG equations for gravity, arXiv:2504.12006.
- A. Bonanno, G. Oglialoro, and D. Zappalà, Gauge and parametrization dependence of quantum Einstein gravity within the proper time flow, Phys. Rev. D 112, 026002 (2025).
- S. Falkenberg and S. D. Odintsov, Gauge dependence of the effective average action in Einstein gravity, Int. J. Mod. Phys. A 13, 607 (1998).