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Related papers: Asymptotically safe gravity as a scalar-tensor the…

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We study the essential renormalization group equation, in which inessential couplings are removed via field redefinitions, for Einstein gravity coupled to a massive scalar field in the presence of a cosmological constant. Our results…

High Energy Physics - Theory · Physics 2025-09-24 Nobuyoshi Ohta , Masatoshi Yamada

We study antigravity, that is having an effective gravitational constant with a negative sign, in scalar-tensor theories originating from $F(R)$-theory and in a Brans-Dicke model with cosmological constant. For the $F(R)$ theory case, we…

General Relativity and Quantum Cosmology · Physics 2014-08-05 V. K. Oikonomou , N. Karagiannakis

A new framework for exploiting information about the renormalization group (RG) behavior of gravity in a dynamical context is discussed. The Einstein-Hilbert action is RG-improved by replacing Newton's constant and the cosmological constant…

High Energy Physics - Theory · Physics 2007-05-23 M. Reuter , H. Weyer

We review aspects of the interplay of asymptotically safe gravity with matter, focusing on the potential predictive power of the quantum scale-symmetry underlying the asymptotically safe fixed point. We explain how an asymptotically safe…

High Energy Physics - Theory · Physics 2019-07-12 Astrid Eichhorn , Aaron Held

We employ the semiclassical approximation to the Wheeler-DeWitt equation in the spatially flat de Sitter Universe to investigate the dynamics of a minimally coupled scalar field near the Planck scale. We find that, contrary to naive…

General Relativity and Quantum Cosmology · Physics 2008-11-07 Corrado Appignani , Roberto Casadio

we investigate the exact renormalization group (RG) in Einstein gravity coupled to N-component scalar field, working in the effective average action formalism and background field method. The truncated evolution equation is obtained for the…

High Energy Physics - Theory · Physics 2009-11-11 L. N. Granda

Asymptotically safe theories of gravitation have received great attention in recent times. In this framework an effective action embodying the basic features of the renormalized flow around the non-gaussian fixed point is derived and its…

High Energy Physics - Theory · Physics 2015-06-04 Alfio Bonanno

We study the inflationary phenomenology of a rescaled Einstein-Gauss-Bonnet gravity. In this framework, the gravitational constant of the Einstein-Hilbert term is rescaled due to effective terms active in the high curvature era. Basically,…

General Relativity and Quantum Cosmology · Physics 2025-03-25 V. K. Oikonomou , Ardit Gkioni , Iason Sdranis , Pyotr Tsyba , Olga Razina

The framework of trans-Planckian asymptotic safety has been shown to generate phenomenological predictions in the Standard Model and in some of its simple new physics extensions. A heuristic approach is often adopted, which bypasses the…

High Energy Physics - Phenomenology · Physics 2023-08-08 Wojciech Kotlarski , Kamila Kowalska , Daniele Rizzo , Enrico Maria Sessolo

In this work we investigate the inflationary phenomenological implications of a recently developed ghost-free Gauss-Bonnet theory of gravity. The resulting theory can be viewed as a scalar Einstein-Gauss-Bonnet theory of gravity, so by…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Shin'ichi Nojiri , S. D. Odintsov , V. K. Oikonomou , N. Chatzarakis , Tanmoy Paul

This is an introduction to asymptotically safe quantum gravity, explaining the main idea of asymptotic safety and how it could solve the problem of predictivity in quantum gravity. In the first part, the concept of an asymptotically safe…

General Relativity and Quantum Cosmology · Physics 2020-03-03 Astrid Eichhorn

We construct a novel Wetterich-type functional renormalization group equation for gravity which encodes the gravitational degrees of freedom in terms of gauge-invariant fluctuation fields. Applying a linear-geometric approximation the…

High Energy Physics - Theory · Physics 2015-04-30 Maximilian Demmel , Frank Saueressig , Omar Zanusso

Two different ways of generalizing Einstein's general theory of relativity with a cosmological constant to Brans-Dicke type scalar-tensor theories are investigated in the linearized field approximation. In the first case a cosmological…

General Relativity and Quantum Cosmology · Physics 2018-02-07 Hatice Özer , Özgür Delice

For a general class of scalar--tensor gravity theories, we discuss how to recover asymptotic freedom regimes when cosmic time $t\to\pm\infty$. Such a feature means that the effective gravitational coupling $G_{eff}\to 0$, while cosmological…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Capozziello , R. de Ritis , A. A. Marino

We propose a scenario with string theory in the deep ultraviolet, an intermediate asymptotically safe scaling regime for gravity and matter, and the Standard Model in the infrared. This could provide a new perspective to tackle challenges…

High Energy Physics - Theory · Physics 2019-11-18 Senarath de Alwis , Astrid Eichhorn , Aaron Held , Jan M. Pawlowski , Marc Schiffer , Fleur Versteegen

The gravitational asymptotic safety program envisions a high-energy completion of the gravitational interactions by an interacting renormalization group fixed point, the Reuter fixed point. The primary tool for investigating this scenario…

High Energy Physics - Theory · Physics 2023-03-01 Frank Saueressig

We study the conformally reduced $R+R^2$ theory of gravity and we show that the theory is asymptotically safe with an ultraviolet critical manifold of dimension three. In particular, we discuss the universality properties of the fixed point…

High Energy Physics - Theory · Physics 2023-07-26 Alfio Maurizio Bonanno , Maria Conti , Sergio Luigi Cacciatori

We analyze the stability of the Einstein static universe by considering homogeneous scalar perturbations in the context of f(R) modified theories of gravity. By considering specific forms of f(R), the stability regions of the solutions are…

General Relativity and Quantum Cosmology · Physics 2012-06-22 Christian G. Boehmer , Lukas Hollenstein , Francisco S. N. Lobo

We discuss the conceptual ideas underlying the Asymptotic Safety approach to the nonperturbative renormalization of gravity. By now numerous functional renormalization group studies predict the existence of a suitable nontrivial ultraviolet…

High Energy Physics - Theory · Physics 2015-12-23 Andreas Nink , Martin Reuter

We explore whether quantum gravity effects within the asymptotic safety paradigm can provide a predictive ultraviolet completion for Abelian gauge theories. We evaluate the effect of quantum gravity fluctuations on the running couplings in…

High Energy Physics - Theory · Physics 2017-05-18 Nicolai Christiansen , Astrid Eichhorn