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200 papers

We study quantum gravity in $2+\epsilon$ dimensions in such a way to preserve the volume preserving diffeomorphism invariance. In such a formulation, we prove the following trinity: the general covariance, the conformal invariance and the…

High Energy Physics - Theory · Physics 2011-08-17 T. Aida , Y. Kitazawa , H. Kawai , M. Ninomiya

Trace-free Einstein gravity is a theory of gravity that is an alternative to general relativity, wherein the cosmological constant arises as an integration constant. However, there are no fully diffeomorphism-invariant action principles…

General Relativity and Quantum Cosmology · Physics 2023-12-07 Merced Montesinos , Diego Gonzalez

Adding terms quadratic in the curvature to the Einstein-Hilbert action renders gravity renormalizable. This property is preserved in the presence of the most general renormalizable couplings with (and of) a generic quantum field theory…

High Energy Physics - Theory · Physics 2018-08-23 Alberto Salvio

Building a consistent Quantum Theory of Gravity is one of the most challenging aspects of modern theoretical physics. In the past couple of years, new attempts have been made along the path of ``asymptotic safety'' through the use of Exact…

High Energy Physics - Theory · Physics 2009-11-10 Daniele Perini

Within the functional renormalization group approach we study the effective QFT of Einstein gravity and one self-interacting scalar coupled to N_f Dirac fermions. We include in our analysis the matter anomalous dimensions induced by all the…

High Energy Physics - Theory · Physics 2010-12-28 G. P. Vacca , O. Zanusso

In recent years it has emerged that the high energy behavior of gravity could be governed by an ultraviolet non-Gaussian fixed point of the (dimensionless) Newton's constant, whose behavior at high energy is thus {\it antiscreened}. This…

High Energy Physics - Theory · Physics 2011-08-17 Alfio Bonanno

The Wilsonian renormalization group (RG) requires Euclidean signature. The conformal factor of the metric then has a wrong-sign kinetic term, which has a profound effect on its RG properties. Generically for the conformal sector, complete…

High Energy Physics - Theory · Physics 2018-08-10 Tim R. Morris

Motivated by Weinberg's asymptotic safety scenario, we investigate the gravitational renormalization group flow in the Einstein-Hilbert truncation supplemented by the wave-function renormalization of the ghost fields. The latter induces…

High Energy Physics - Theory · Physics 2014-11-20 Kai Groh , Frank Saueressig

A theory of quantum gravity consists of a gravitational framework which, unlike general relativity, takes into account the quantum character of matter. In spite of impressive advances, no fully satisfactory, self-consistent and empirically…

General Relativity and Quantum Cosmology · Physics 2025-06-23 R. Muciño , E. Okon , D. Sudarsky , M. Wiedemann

Motivated by recent evidence indicating that Quantum Einstein Gravity (QEG) might be nonperturbatively renormalizable, the exact renormalization group equation of QEG is evaluated in a truncation of theory space which generalizes the…

High Energy Physics - Theory · Physics 2008-11-26 O. Lauscher , M. Reuter

Recent technical and conceptual advancements in the asymptotic safety approach to quantum gravity have enabled studies of the UV completion of Lorentzian Einstein gravity, emphasizing the role of the state dependence. We present here the…

High Energy Physics - Theory · Physics 2025-02-18 Edoardo D'Angelo , Renata Ferrero , Markus B. Fröb

The quantum Einstein gravity is treated by the functional renormalization group method using the Einstein-Hilbert action. The ultraviolet non-Gaussian fixed point is determined and its corresponding exponent of the correlation length is…

High Energy Physics - Theory · Physics 2015-06-16 S. Nagy , B. Fazekas , L. Juhasz , K. Sailer

We compute the ghost anomalous dimension within the asymptotic-safety scenario for quantum gravity. For a class of covariant gauge fixings and using a functional RG scheme, the anomalous dimension $\eta_c$ is negative, implying an improved…

High Energy Physics - Theory · Physics 2010-05-19 Astrid Eichhorn , Holger Gies

We present and discuss well known conditions for ultraviolet finiteness and asymptotic safety. The requirements for complete absence of ultraviolet divergences in quantum field theories and existence of a non-trivial fixed point for…

High Energy Physics - Theory · Physics 2022-04-22 Leslaw Rachwal

We explore the cosmological dynamics of an effective f(R) model constructed from a renormalisation group (RG) improvement of the Einstein--Hilbert action, using the non-perturbative beta functions of the exact renormalisation group…

General Relativity and Quantum Cosmology · Physics 2012-03-20 Mark Hindmarsh , Ippocratis D. Saltas

The anomalous scaling of Newton's constant around the Reuter fixed point is dynamically computed using the functional flow equation approach. Specifically, we thoroughly analyze the flow of the most general conformally reduced…

High Energy Physics - Theory · Physics 2023-09-28 Alfio Bonanno , Maria Conti , Dario Zappalà

On the basis of a limited number of reasonable axioms, we discuss the classification of all the possible universality classes of diffeomorphisms invariant metric theories of quantum gravity. We use the language of the renormalization group…

High Energy Physics - Theory · Physics 2021-08-05 Riccardo Martini , Alessandro Ugolotti , Omar Zanusso

In this paper we introduce a perturbatively super-renormalizable and unitary theory of quantum gravity in any dimension D. The theory presents two entire functions, a.k.a. "form factors", and a finite number of local operators required by…

High Energy Physics - Theory · Physics 2014-01-23 Leonardo Modesto

The quantum gravitational contribution to the renormalization group behavior of the electric charge in Einstein-Maxwell theory with a cosmological constant is considered. Quantum gravity is shown to lead to a contribution to the running…

High Energy Physics - Theory · Physics 2008-11-26 David J. Toms

We perform canonical quantization of General Relativity, as an effective quantum field theory below the Planck scale, within the BRST-invariant framework. We show that the promotion of constraints to dynamical equations of motion for…

High Energy Physics - Theory · Physics 2024-09-30 Lasha Berezhiani , Gia Dvali , Otari Sakhelashvili