Gabriele Giacometti | Searcharxiv

arXiv2026

Quantum gravity contributions to the gauge and Yukawa couplings in proper time flow

We derive quantum gravity contributions to the beta functions of the gauge and Yukawa couplings of a matter theory using the Schwinger proper-time flow equation. Working in the Einstein-Hilbert truncation, we investigate the gauge-fixing and regulator dependence of the corresponding renormalization group equations. We quantify the sensitivity of our results on unphysical parameters by evaluating the gravitational correction to the running matter couplings at the interactive fixed point of gravity and we compare our findings with existing determinations in alternative schemes. We finally confront the derived contributions with the typical size they should assume to generate observable low-scale predictions in the Standard Model and in several scenarios of new physics.

hep-ph↗

arXiv2025

On the universal content of the proper time flow in scalar and Yang-Mills theories

We investigate the perturbative structure of the proper time renormalization group flow in scalar and Yang-Mills theories. Although the PT flow does not belong to the class of exact functional renormalization group equations, we show that it correctly reproduces the universal coefficients of the $β$-functions at one and two loops. For the ${\rm O(N)}$ scalar theory, we derive the one- and two-loop contributions to the running quartic coupling and also confirm the expected anomalous dimension. For the ${\rm SU(N)}$ Yang-Mills theory, using the background field method, we compute the gauge coupling renormalization recovering the correct two-loop $β$-function without generating any gauge-symmetry-violating term. These results highlight that, despite its limitations for reconstructing the full effective action, the PT flow retains the essential universal content of renormalization, accounting for its reliability in diverse applications ranging from statistical models to quantum gravity.

hep-th↗