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Related papers: On quantum gravity, Asymptotic Safety, and paramag…

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Asymptotic safety is a promising mechanism for obtaining a consistent and predictive quantum theory for gravity. The ADM formalism allows to introduce a (Euclidean) time-direction in this framework. It equips spacetime with a foliation…

High Energy Physics - Theory · Physics 2024-02-05 Guus Korver , Frank Saueressig , Jian Wang

Ultraviolet fixed point functions of the functional renormalisation group equation for $f(R)$-gravity coupled to matter fields are discussed. The metric is split via the exponential parameterisation into a background and a fluctuating…

High Energy Physics - Theory · Physics 2019-01-09 Natalia Alkofer

We investigate the non-perturbative renormalization group behavior of the gauge coupling constant using a truncated form of the functional flow equation for the effective average action of the Yang-Mills-gravity system. We find a non-zero…

High Energy Physics - Theory · Physics 2015-05-14 Jan-Eric Daum , Ulrich Harst , Martin Reuter

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

We hereby present a class of multidimensional higher derivative theories of gravity that realizes an ultraviolet completion of Einstein general relativity. This class is marked by a "non-polynomal" entire function (form factor), which…

High Energy Physics - Theory · Physics 2013-05-30 Leonardo Modesto

We discuss the non-perturbative renormalization group flow of Quantum Electrodynamics (QED) coupled to Quantum Einstein Gravity (QEG) and explore the possibilities for defining its continuum limit at a fixed point that would lead to a…

High Energy Physics - Theory · Physics 2015-05-27 Ulrich Harst , Martin Reuter

High-energy completeness of quantum electrodynamics (QED) can be induced by an interacting ultraviolet fixed point of the renormalization flow. We provide evidence for the existence of two of such fixed points in the subspace spanned by the…

High Energy Physics - Theory · Physics 2022-01-24 Holger Gies , Jobst Ziebell

A real space renormalization group technique, based on the hierarchical baby-universe structure of a typical dynamically triangulated manifold, is used to study scaling properties of 2d and 4d lattice quantum gravity. In 4d, the…

High Energy Physics - Theory · Physics 2009-10-28 Z. Burda , J. -P. Kownacki , A. Krzywicki

Combining asymptotically safe quantum gravity with a tensor field theory, we exhibit the first example of a theory with gravity and scalar fields in four dimensions which may realize asymptotic safety at a non-vanishing value of the scalar…

High Energy Physics - Theory · Physics 2025-01-20 Astrid Eichhorn , Razvan Gurau , Zois Gyftopoulos

4D Einstein gravity coupled to scalars and abelian gauge fields in its 2-Killing vector reduction is shown to be quasi-renormalizable to all loop orders at the expense of introducing infinitely many essential couplings. The latter can be…

High Energy Physics - Theory · Physics 2015-06-26 M. Niedermaier

We show that perturbative quantum gravity based on the Einstein-Hilbert action, has a novel continuum limit. The renormalized trajectory emanates from the Gaussian fixed point along (marginally) relevant directions but enters the…

High Energy Physics - Theory · Physics 2021-06-09 Matthew Kellett , Alex Mitchell , Tim R. Morris

The asymptotic-safety paradigm posits that the symmetry of quantum theories of gravity and matter is enhanced to quantum scale symmetry, i.e., scale symmetry in the presence of quantum fluctuations, at very high energies. To achieve such a…

High Energy Physics - Theory · Physics 2022-12-16 Astrid Eichhorn , Marc Schiffer

It is well known that Einstein gravity is non-renormalizable; however a generalized approach is proposed that leads to Einstein gravity {\it after} renormalization. This them implies that at least one candidate for quantum gravity treats…

General Relativity and Quantum Cosmology · Physics 2009-10-28 A. Y. Shiekh

We show that, by using amplitude-based resummation techniques for Feynman's formulation of Einstein's theory, we get quantum field theoretic 'first principles' predictions for the UV fixed-point values of the dimensionless gravitational and…

General Relativity and Quantum Cosmology · Physics 2009-10-13 B. F. L. Ward

If gravity is asymptotically safe, operators will exhibit anomalous scaling at the ultraviolet fixed point in a way that makes the theory effectively two-dimensional. A number of independent lines of evidence, based on different approaches…

General Relativity and Quantum Cosmology · Physics 2019-04-10 S. Carlip

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

We discover that chiral symmetry does not act as an infrared attractor of the renormalization group flow under the impact of quantum gravity fluctuations. Thus, observationally viable quantum gravity models must respect chiral symmetry. In…

General Relativity and Quantum Cosmology · Physics 2017-02-08 Astrid Eichhorn , Stefan Lippoldt

We analyze a proper time renormalization group equation for Quantum Einstein Gravity in the Einstein-Hilbert truncation and compare its predictions to those of the conceptually different exact renormalization group equation of the effective…

High Energy Physics - Theory · Physics 2008-11-26 A. Bonanno , M. Reuter

Wetterich's equation provides a powerful tool for investigating the existence and universal properties of renormalization group fixed points exhibiting quantum scale invariance. Motivated by recent works on asymptotically safe scalar-tensor…

High Energy Physics - Theory · Physics 2023-01-11 Cristobal Laporte , Nora Locht , Antonio D. Pereira , Frank Saueressig

The gauge hierarchy problem could find a solution within the scenario of asymptotic safety for quantum gravity. We discuss a "resurgence mechanism" where the running dimensionless coupling responsible for the Higgs scalar mass first…

High Energy Physics - Theory · Physics 2017-05-16 Christof Wetterich , Masatoshi Yamada