scholarly journals On the Vilkovisky-DeWitt approach and renormalization group in effective quantum gravity

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Breno L. Giacchini ◽  
Tibério de Paula Netto ◽  
Ilya L. Shapiro
Keyword(s):  
Renormalization Group ◽  
Quantum Gravity ◽  
Effective Action ◽  
Planck Scale ◽  
Renormalization Group Flow ◽  
Higher Derivative ◽  
Gauge Fixing ◽  
Total Action ◽  
The One ◽  
Group Flow

Abstract The effective action in quantum general relativity is strongly dependent on the gauge-fixing and parametrization of the quantum metric. As a consequence, in the effective approach to quantum gravity, there is no possibility to introduce the renormalization-group framework in a consistent way. On the other hand, the version of effective action proposed by Vilkovisky and DeWitt does not depend on the gauge-fixing and parametrization off- shell, opening the way to explore the running of the cosmological and Newton constants as well as the coefficients of the higher-derivative terms of the total action. We argue that in the effective framework the one-loop beta functions for the zero-, two- and four-derivative terms can be regarded as exact, that means, free from corrections coming from the higher loops. In this perspective, the running describes the renormalization group flow between the present-day Hubble scale in the IR and the Planck scale in the UV.

scholarly journals ASYMPTOTIC SAFETY IN HIGHER-DERIVATIVE GRAVITY

2009 ◽  
Vol 24 (28) ◽  
pp. 2233-2241 ◽  
Author(s):  
DARIO BENEDETTI ◽  
PEDRO F. MACHADO ◽  
FRANK SAUERESSIG
Keyword(s):  
Fixed Point ◽  
Renormalization Group ◽  
Renormalization Group Flow ◽  
Functional Renormalization Group ◽  
Asymptotic Safety ◽  
Higher Derivative ◽  
Gravity Theories ◽  
Group Flow ◽  
Nonperturbative Renormalization

We study the nonperturbative renormalization group flow of higher-derivative gravity employing functional renormalization group techniques. The nonperturbative contributions to the β-functions shift the known perturbative ultraviolet fixed point into a nontrivial fixed point with three UV-attractive and one UV-repulsive eigendirections, consistent with the asymptotic safety conjecture of gravity. The implication of this transition on the unitarity problem, typically haunting higher-derivative gravity theories, is discussed.

The renormalization group in perturbative quantum gravity

2021 ◽  
pp. 488-493
Author(s):  
Iosif L. Buchbinder ◽  
Ilya L. Shapiro
Keyword(s):  
Renormalization Group ◽  
Quantum Gravity ◽  
Minimal Subtraction Scheme ◽  
Loop Approximation ◽  
Renormalization Group Equations ◽  
Gauge Fixing ◽  
Perturbative Renormalization ◽  
Fourth Derivative ◽  
Perturbative Quantum ◽  
The One

This is a short chapter summarizing the main results concerning the renormalization group in models of pure quantum gravity, without matter fields. The chapter starts with a critical analysis of non-perturbative renormalization group approaches, such as the asymptotic safety hypothesis. After that, it presents solid one-loop results based on the minimal subtraction scheme in the one-loop approximation. The polynomial models that are briefly reviewed include the on-shell renormalization group in quantum general relativity, and renormalization group equations in fourth-derivative quantum gravity and superrenormalizable models. Special attention is paid to the gauge-fixing dependence of the renormalization group trajectories.

scholarly journals IRREVERSIBILITY OF THE RENORMALIZATION GROUP FLOW IN TWO-DIMENSIONAL QUANTUM GRAVITY

1992 ◽  
Vol 07 (31) ◽  
pp. 2943-2955 ◽  
Author(s):  
DAVID KUTASOV
Keyword(s):  
Renormalization Group ◽  
String Theory ◽  
Quantum Gravity ◽  
Degrees Of Freedom ◽  
Two Dimensional ◽  
Renormalization Group Flow ◽  
Group Flow

We argue that the torus partition sum in 2D (super) gravity, which counts physical states in the theory, is a decreasing function of the renormalization group scale. As an application we chart the space of [Formula: see text] models coupled to (super) gravity, confirming and extending ideas due to A. Zamolodchikov, and discuss briefly string theory, where our results imply that the number of degrees of freedom decreases with time.

scholarly journals Center-Vortex Loops with One Self-Intersection

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Julian Moosmann ◽  
Ralf Hofmann
Keyword(s):  
Renormalization Group ◽  
Effective Action ◽  
Noise Level ◽  
Coarse Graining ◽  
Renormalization Group Flow ◽  
Yang Mills ◽  
Vortex Loops ◽  
Center Vortex ◽  
Group Flow ◽  
Ordered State

We investigate the 2D behavior of one-fold self-intersecting, topologically stabilized center-vortex loops in the confining phase of an SU(2) Yang-Mills theory. This coarse-graining is described by curve-shrinking evolution of center-vortex loops immersed in a flat 2D plane driving the renormalization-group flow of an effective “action.” We observe that the system evolves into a highly ordered state at finite noise level, and we speculate that this feature is connected with 2D planar high Tc superconductivity in FeAs systems.

scholarly journals Renormalization-group flow of the effective action of cosmological large-scale structures

2017 ◽  
Vol 2017 (01) ◽  
pp. 048-048 ◽  
Author(s):  
Stefan Floerchinger ◽  
Mathias Garny ◽  
Nikolaos Tetradis ◽  
Urs Achim Wiedemann
Keyword(s):  
Renormalization Group ◽  
Effective Action ◽  
Large Scale ◽  
Renormalization Group Flow ◽  
Large Scale Structures ◽  
Scale Structures ◽  
Group Flow

scholarly journals Unimodular quantum gravity: steps beyond perturbation theory

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Gustavo P. de Brito ◽  
Antonio D. Pereira
Keyword(s):  
Fixed Point ◽  
Perturbation Theory ◽  
Renormalization Group ◽  
Quantum Gravity ◽  
Symmetry Breaking ◽  
Coarse Graining ◽  
Renormalization Group Flow ◽  
Anomalous Dimensions ◽  
Group Flow

Abstract The renormalization group flow of unimodular quantum gravity is computed by taking into account the graviton and Faddeev-Popov ghosts anomalous dimensions. In this setting, a ultraviolet attractive fixed point is found. Symmetry-breaking terms induced by the coarse-graining procedure are introduced and their impact on the flow is analyzed. A discussion on the equivalence of unimodular quantum gravity and standard full diffeomorphism invariant theories is provided beyond perturbation theory.

scholarly journals ON THE POSSIBILITY OF QUANTUM GRAVITY EFFECTS AT ASTROPHYSICAL SCALES

2006 ◽  
Vol 15 (12) ◽  
pp. 2011-2028 ◽  
Author(s):  
MARTIN REUTER ◽  
HOLGER WEYER
Keyword(s):  
Dark Matter ◽  
Renormalization Group ◽  
Quantum Gravity ◽  
Einstein Gravity ◽  
Scale Dependence ◽  
Renormalization Group Flow ◽  
Gravity Effects ◽  
Group Flow ◽  
Nonperturbative Renormalization

The nonperturbative renormalization group flow of quantum Einstein gravity (QEG) is reviewed. It is argued that at large distances there could be strong renormalization effects, including a scale dependence of Newton's constant, which mimic the presence of dark matter at galactic and cosmological scales.

scholarly journals Consistent closure of renormalization group flow equations in quantum gravity

2014 ◽  
Vol 89 (8) ◽  
Author(s):  
Alessandro Codello ◽  
Giulio D’Odorico ◽  
Carlo Pagani
Keyword(s):  
Renormalization Group ◽  
Quantum Gravity ◽  
Renormalization Group Flow ◽  
Flow Equations ◽  
Group Flow
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