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Related papers: Running Immirzi Parameter and Asymptotic Safety

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We compare the recently formulated multifractional spacetimes with field theories of quantum gravity based on the renormalization group (RG), such as asymptotic safety and Ho\v{r}ava--Lifshitz gravity. The change of spacetime dimensionality…

High Energy Physics - Theory · Physics 2013-07-31 Gianluca Calcagni

The running of the non-minimal parameter (\xi) of the interaction of the real scalar field and scalar curvature is explored within the non-perturbative setting of the functional renormalization group (RG). We establish the RG flow in curved…

High Energy Physics - Theory · Physics 2015-05-08 Ilya L. Shapiro , Poliane M. Teixeira , Andreas Wipf

The possibility of a minimal physical length in quantum gravity is discussed within the asymptotic safety approach. Using a specific mathematical model for length measurements ("COM microscope") it is shown that the spacetimes of Quantum…

High Energy Physics - Theory · Physics 2008-11-26 Martin Reuter , Jan-Markus Schwindt

Using the Batalin-Vilkovisky technique and the background field method the proof of gauge invariant renormalizability is elaborated for a generic model of quantum gravity which is diffeomorphism invariant and has no other, potentially…

High Energy Physics - Theory · Physics 2019-08-07 Peter M. Lavrov , Ilya L. Shapiro

In this article we apply background-independent renormalization group methods to spin foam quantum gravity. It is aimed at extending and elucidating the analysis of a companion letter, in which the existence of a fixed point in the…

General Relativity and Quantum Cosmology · Physics 2017-07-21 Benjamin Bahr , Sebastian Steinhaus

The current understanding of renormalization in quantum gravity (QG) is based on the fact that UV divergences of effective actions in the covariant QG models are covariant local expressions. This fundamental statement plays a central role…

High Energy Physics - Theory · Physics 2024-07-30 P. M. Lavrov , I. L. Shapiro

We reconsider the conceptual foundations of the renormalization-group (RG) formalism, and prove some rigorous theorems on the regularity properties and possible pathologies of the RG map. Regarding regularity, we show that the RG map,…

High Energy Physics - Lattice · Physics 2015-06-25 A. C. D. van Enter , R. Fernandez , A. D. Sokal

Asymptotic Safety, based on a non-Gaussian fixed point of the gravitational renormalization group flow, provides an elegant mechanism for completing the gravitational force at sub-Planckian scales. At high energies the fixed point controls…

High Energy Physics - Theory · Physics 2017-06-28 Alfio Bonanno , Frank Saueressig

We review Holst formalism and we discuss dynamical equivalence with standard GR (in dimension 4). Holst formalism is written for a spin coframe field $e^I_\mu$ and a $Spin(3,1)$-connection $\omega^{IJ}_\mu$ on spacetime $M$ and it depends…

General Relativity and Quantum Cosmology · Physics 2024-02-27 L. Fatibene , A. Orizzonte , A. Albano , S. Coriasco , M. Ferraris , S. Garruto , N. Morandi

The Wilsonian renormalization group (RG) properties of the conformal factor of the metric are profoundly altered by the fact that it has a wrong-sign kinetic term. The result is a novel perturbative continuum limit for quantum gravity,…

High Energy Physics - Theory · Physics 2020-07-15 Alex Mitchell , Tim R. Morris

A nonconventional renormalization-group (RG) treatment close to and below four dimensions is used to explore, in a unified and systematic way, the low-temperature properties of a wide class of systems in the influence domain of their…

Statistical Mechanics · Physics 2009-11-13 M. T. Mercaldo , L. De Cesare , I. Rabuffo , A. Caramico D'Auria

We perform the thermal Renormalization Group (RG) study of the Asymptotically Safe (AS) quantum gravity in the Einstein-Hilbert truncation by relating the temperature parameter to the running RG scale as $T \equiv k_T = \tau k$ (in natural…

General Relativity and Quantum Cosmology · Physics 2025-04-04 E. Nyergesy , I. G. Márián , E. Meskhi , Y. Turovtsi-Shiutev , I. Nandori

We promote the Immirzi parameter to be a minimally coupled scalar field and we analyzed the Hamiltonian constraints in the framework of Loop Quantum Gravity without the time gauge. Proper SU(2) connections can be defined and a term…

General Relativity and Quantum Cosmology · Physics 2009-11-05 Francesco Cianfrani , Giovanni Montani

An so(4,C)-covariant hamiltonian formulation of a family of generalized Hilbert-Palatini actions depending on a parameter (the so called Immirzi parameter) is developed. It encompasses the Ashtekar-Barbero gravity which serves as a basis of…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Sergei Alexandrov

We investigate the ultraviolet behaviour of quantum gravity within a functional renormalisation group approach. The present setup includes the full ghost and graviton propagators and, for the first time, the dynamical graviton three-point…

High Energy Physics - Theory · Physics 2016-05-23 Nicolai Christiansen , Benjamin Knorr , Jan Meibohm , Jan M. Pawlowski , Manuel Reichert

We review some of our recent results concerning the relationship between the Real-Space Renormalization Group method and Quantum Groups. We show this relation by applying real-space RG methods to study two quantum group invariant…

High Energy Physics - Theory · Physics 2016-11-03 Miguel A. Martin-Delgado , German Sierra

A perturbative quantum theory of the 2-Killing vector reduction of general relativity is constructed. Although non-renormalizable in the standard sense, we show that to all orders of the loop expansion strict cut-off independence can be…

High Energy Physics - Theory · Physics 2014-11-18 M. Niedermaier

In this essay and utilizing the holographic Renormalization Group (RG) flow, we demonstrate how the effective action of a non-gravitating quantum field theory in the ultraviolet (UV) develops an Einstein-Hilbert term in the infrared (IR).…

High Energy Physics - Theory · Physics 2026-05-20 M. M. Sheikh-Jabbari , V. Taghiloo

In one-dimensional quantum wires the interplay of electron correlations and impurities strongly influences the low-energy physics. The diversity of energy scales and the competition of correlations in interacting Fermi systems can be…

Strongly Correlated Electrons · Physics 2024-09-02 Sabine Andergassen

Within the asymptotic safety program, it is possible to construct renormalization group (RG) improved spacetimes by replacing the gravitational coupling $G$ by its running counterpart $G(k)$, and subsequently identifying the RG scale $k$…

General Relativity and Quantum Cosmology · Physics 2023-12-20 Jens Boos