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Related papers: Running Immirzi Parameter and Asymptotic Safety

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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

The asymptotic safety program strives for a consistent description of gravity as a non-perturbatively renormalizable quantum field theory. In this framework the gravitational interactions are encoded in a renormalization group flow…

General Relativity and Quantum Cosmology · Physics 2019-01-08 Frank Saueressig , Giulia Gubitosi , Chris Ripken

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

We study asymptotically safe gravity with Einstein-Hilbert truncation taking into account the renormalization group running of both gravitational and cosmological constants. We show the classical behavior of the theory is equivalent to a…

High Energy Physics - Theory · Physics 2011-11-03 Yi-Fu Cai , Damien A. Easson

We study fixed points of quantum gravity with renormalisation group methods, and a procedure to remove convergence-limiting poles from the flow. The setup is tested within the $f(R)$ approximation for gravity by solving exact recursive…

General Relativity and Quantum Cosmology · Physics 2019-07-03 Kevin G. Falls , Daniel F. Litim , Jan Schröder

The functional renormalization group equation for projectable Ho\v{r}ava-Lifshitz gravity is used to derive the non-perturbative beta functions for the Newton's constant, cosmological constant and anisotropy parameter. The resulting coupled…

High Energy Physics - Theory · Physics 2015-06-17 Adriano Contillo , Stefan Rechenberger , Frank Saueressig

We review the asymptotic safety scenario for quantum gravity and the role and implications of an underlying ultraviolet fixed point. We discuss renormalisation group techniques employed in the fixed point search, analyse the main picture at…

High Energy Physics - Theory · Physics 2009-06-09 Daniel F. Litim

The methods of the renormalization group and the $\varepsilon$-expansion are applied to quantum gravity revealing the existence of an asymptotically safe fixed point in spacetime dimensions higher than two. To facilitate this, physical…

High Energy Physics - Theory · Physics 2018-01-04 Kevin Falls

Asymptotic Safety implies that observables including scattering amplitudes remain finite at the highest energy scales. Traditionally, this feature is connected to an interacting fixed point of the Wilsonian renormalization group that…

High Energy Physics - Theory · Physics 2022-10-31 Benjamin Knorr , Chris Ripken , Frank Saueressig

The Immirzi parameter is a constant appearing in the general relativity action used as a starting point for the loop quantization of gravity. The parameter is commonly believed not to show up in the equations of motion, because it appears…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Alejandro Perez , Carlo Rovelli

We use the functional renormalization group equation for the effective average action to study the fixed point structure of gravity-fermion systems on a curved background spacetime. We approximate the effective average action by the…

High Energy Physics - Theory · Physics 2020-10-06 Jesse Daas , Wouter Oosters , Frank Saueressig , Jian Wang

Application of the Weinberg's conditions of asymptotic safety to amplitudes and not to couplings of the effective action can help to uniquely define the running in the UV and avoid some of the asymptotic safety program problems. The idea is…

High Energy Physics - Theory · Physics 2021-02-17 Jan H. Kwapisz , Krzysztof A. Meissner

In the average action approach to the quantization of gravity the fundamental requirement of "background independence" is met by actually introducing a background metric but leaving it completely arbitrary. The associated Wilsonian…

General Relativity and Quantum Cosmology · Physics 2010-03-02 Elisa Manrique , Martin Reuter

We discuss the compatibility of quantum gravity with dynamical matter degrees of freedom. Specifically, we present bounds we obtained in [1] on the allowed number and type of matter fields within asymptotically safe quantum gravity. As a…

General Relativity and Quantum Cosmology · Physics 2023-07-19 P. Donà , Astrid Eichhorn , Roberto Percacci

We apply real-space RG methods to study two quantum group invariant Hamiltonians, that of the XXZ model and the Ising model in a transverse field defined in an open chain with appropiate boundary terms. The quantum group symmetry is…

Condensed Matter · Physics 2008-11-26 Miguel A. Martin-Delgado , German Sierra

Realizing a quantum theory for gravity based on Asymptotic Safety hinges on the existence of a non-Gaussian fixed point of the theory's renormalization group flow. In this work, we use the functional renormalization group equation for the…

High Energy Physics - Theory · Physics 2015-09-30 Maximilian Demmel , Frank Saueressig , Omar Zanusso

It is well known in quantum field theory that the off-shell effective action depends on the gauge choice and field parametrization used in calculating it. Nevertheless, the typical scheme in which the scenario of asymptotically safe gravity…

High Energy Physics - Theory · Physics 2018-10-15 Dario Benedetti

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

Recent results based on renormalization group approaches to Quantum Gravity suggest that the Newton's and cosmological constants should be treated as dynamical variables whose evolution depend on the characteristic energy scale of the…

General Relativity and Quantum Cosmology · Physics 2018-05-08 S. J. Gabriele Gionti

Asymptotic Safety provides an elegant mechanism for obtaining a consistent high-energy completion of gravity and gravity-matter systems. Following the initial idea by Steven Weinberg, the construction builds on an interacting fixed point of…

High Energy Physics - Theory · Physics 2022-01-05 Cristobal Laporte , Antonio D. Pereira , Frank Saueressig , Jian Wang