- Open Access
Universal content of the proper time flow in scalar and Yang-Mills theories
Phys. Rev. D 113, 045020 – Published 23 February, 2026
DOI: https://doi.org/10.1103/dsgp-mlkp
Abstract
We investigate the perturbative structure of the proper time renormalization group flow in scalar and Yang-Mills theories. Although the proper time flow does not belong to the class of exact functional renormalization group equations, we show that it correctly reproduces the universal coefficients of the functions at one and two loops. For the O(N) scalar theory, we derive the one- and two-loop contributions to the running quartic coupling and also confirm the expected anomalous dimension. For the SU(N) Yang-Mills theory, using the background field method, we compute the gauge coupling renormalization recovering the correct two-loop function without generating any gauge-symmetry–violating terms. These results highlight that, despite its limitations for reconstructing the full effective action, the proper time flow retains the essential universal content of renormalization, accounting for its reliability in diverse applications ranging from statistical models to quantum gravity.
Physics Subject Headings (PhySH)
Article Text
References (37)
- K. G. Wilson and J. B. Kogut, The renormalization group and the epsilon expansion, Phys. Rep. 12, 75 (1974).
- J. Berges, N. Tetradis, and C. Wetterich, Nonperturbative renormalization flow in quantum field theory and statistical physics, Phys. Rep. 363, 223 (2002).
- N. Dupuis, L. Canet, A. Eichhorn, W. Metzner, J. M. Pawlowski, M. Tissier, and N. Wschebor, The nonperturbative functional renormalization group and its applications, Phys. Rep. 910, 1 (2021).
- C. Wetterich, Exact evolution equation for the effective potential, Phys. Lett. B 301, 90 (1993).
- T. R. Morris, The exact renormalization group and approximate solutions, Int. J. Mod. Phys. A 09, 2411 (1994).
- M. Reuter and C. Wetterich, Effective average action for gauge theories and exact evolution equations, Nucl. Phys. B417, 181 (1994).
- D. F. Litim and J. M. Pawlowski, Perturbation theory and renormalization group equations, Phys. Rev. D 65, 081701 (2002).
- D. F. Litim and J. M. Pawlowski, Completeness and consistency of renormalisation group flows, Phys. Rev. D 66, 025030 (2002).
- T. Papenbrock and C. Wetterich, Two loop results from one loop computations and nonperturbative solutions of exact evolution equations, Z. Phys. C 65, 519 (1995).
- F. J. Wegner and A. Houghton, Renormalization group equation for critical phenomena, Phys. Rev. A 8, 401 (1973).
- S.-B. Liao and J. Polonyi, Blocking transformation in field theory, Ann. Phys. (N.Y.) 222, 122 (1993).
- S.-B. Liao, J. Polonyi, and D.-p. Xu, Quantum and thermal fluctuations in field theory, Phys. Rev. D 51, 748 (1995).
- S.-B. Liao, On connection between momentum cutoff and the proper time regularizations, Phys. Rev. D 53, 2020 (1996).
- A. Bonanno and D. Zappala, Nonperturbative renormalization group approach for a scalar theory in higher derivative gravity, Phys. Rev. D 55, 6135 (1997).
- A. Bonanno and D. Zappala, Two loop results from the derivative expansion of the blocked action, Phys. Rev. D 57, 7383 (1998).
- A. Bonanno, V. Branchina, H. Mohrbach, and D. Zappala, Wegner-Houghton equation and derivative expansion, Phys. Rev. D 60, 065009 (1999).
- M. Oleszczuk, A symmetry preserving cutoff regularization, Z. Phys. C 64, 533 (1994).
- S.-B. Liao, Operator cutoff regularization and renormalization group in Yang-Mills theory, Phys. Rev. D 56, 5008 (1997).
- A. Bonanno and D. Zappala, Towards an accurate determination of the critical exponents with the renormalization group flow equations, Phys. Lett. B 504, 181 (2001).
- D. F. Litim and J. M. Pawlowski, Predictive power of renormalization group flows: A comparison, Phys. Lett. B 516, 197 (2001).
- M. Mazza and D. Zappala, Proper time regulator and renormalization group flow, Phys. Rev. D 64, 105013 (2001).
- D. F. Litim and D. Zappala, Ising exponents from the functional renormalisation group, Phys. Rev. D 83, 085009 (2011).
- A. Bonanno, A. Codello, and D. Zappalà, Structural aspects of FRG in quantum tunneling computations, Ann. Phys. (Amsterdam) 445, 169090 (2022).
- A. Bonanno and M. Reuter, Proper time flow equation for gravity, J. High Energy Phys. 02 (2005) 035.
- A. Bonanno and F. Guarnieri, Universality and symmetry breaking in conformally reduced quantum gravity, Phys. Rev. D 86, 105027 (2012).
- A. Bonanno, M. Conti, and D. Zappalà, The conformal sector of quantum Einstein gravity beyond the local potential approximation, Phys. Lett. B 847, 138311 (2023).
- 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).
- A. Bonanno, E. Glaviano, and G. P. Vacca, Proper-time functional renormalization in scalar models coupled to gravity, arXiv:2508.00807.
- A. M. Bonanno, R. A. Konoplya, G. Oglialoro, and A. Spina, Regular black holes from proper-time flow in quantum gravity and their quasinormal modes, shadow and Hawking radiation, J. Cosmol. Astropart. Phys. 12 (2025) 042.
- K. Falls and R. Ferrero, Asymptotic safety within on-shell perturbation theory, J. High Energy Phys. 08 (2025) 173.
- D. F. Litim and J. M. Pawlowski, Wilsonian flows and background fields, Phys. Lett. B 546, 279 (2002).
- C. Wetterich, Simplified functional flow equation, Phys. Lett. B 864, 139435 (2025).
- S. P. de Alwis, Exact RG flow equations and quantum gravity, J. High Energy Phys. 03 (2017) 118.
- A. Bonanno, S. Lippoldt, R. Percacci, and G. P. Vacca, On exact proper time Wilsonian RG flows, Eur. Phys. J. C 80, 249 (2020).
- J. S. Schwinger, On gauge invariance and vacuum polarization, Phys. Rev. 82, 664 (1951).
- D. Zappala, Perturbative and nonperturbative aspects of the proper time renormalization group, Phys. Rev. D 66, 105020 (2002).
- L. F. Abbott, The background field method beyond one loop, Nucl. Phys. B185, 189 (1981).