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Related papers: On unimodular quantum gravity

200 papers

We analyze $SO(N)$ and $SU(N)$ gauge theories with scalars in adjoint and fundamental representations, coupled to renormalisable, classically scale invariant gravity. In the specific case of $SO(12),$ we show that the quantum field theory…

High Energy Physics - Theory · Physics 2019-10-23 Martin B Einhorn , D R Timothy Jones

We find considerable evidence supporting the conjecture that four-dimensional Quantum Einstein Gravity is ``asymptotically safe'' in Weinberg's sense. This would mean that the theory is likely to be nonperturbatively renormalizable and thus…

High Energy Physics - Theory · Physics 2009-11-07 O. Lauscher , M. Reuter

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 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

BRST-invariant action of general relativity in the unimodular gauge proposed by Baulieu is studied without using perturbative expansions. The expression for the path integral in the unimodular gauge is reduced to a form in which a…

High Energy Physics - Theory · Physics 2021-07-16 Ryuichi Nakayama

A hallmark of non-perturbative theories of quantum gravity is the absence of a fixed background geometry, and therefore the absence in a Planckian regime of any notion of length or scale that is defined a priori. This has potentially…

High Energy Physics - Theory · Physics 2020-02-06 J. Ambjorn , J. Gizbert-Studnicki , A. Goerlich , J. Jurkiewicz , R. Loll

We construct a Weyl transverse diffeomorphism invariant theory of teleparallel gravity by employing the Weyl compensator formalism. The low-energy dynamics has a single spin two gravition without a scalar degree of freedom. By construction,…

General Relativity and Quantum Cosmology · Physics 2023-05-31 Yu Nakayama

A quantization of unimodular gravity is described, which results in a quantum effective action which is also unimodular, ie a function of a metric with fixed determinant. A consequence is that contributions to the energy momentum tensor of…

High Energy Physics - Theory · Physics 2013-05-29 Lee Smolin

We highlight how the existence of an ultraviolet completion for interacting Standard-Model type matter puts constraints on the viable microscopic dynamics of asymptotically safe quantum gravity within truncated Renormalization Group flows.…

General Relativity and Quantum Cosmology · Physics 2017-12-01 Astrid Eichhorn , Aaron Held

The asymptotic safety scenario in quantum gravity is reviewed, according to which a renormalizable quantum theory of the gravitational field is feasible which reconciles asymptotically safe couplings with unitarity. All presently known…

General Relativity and Quantum Cosmology · Physics 2010-11-02 M. Niedermaier

We consider the asymptotic-safety scenario for quantum gravity which constructs a non-perturbatively renormalisable quantum gravity theory with the help of the functional renormalisation group. We verify the existence of a non-Gaussian…

High Energy Physics - Theory · Physics 2009-11-10 Astrid Eichhorn , Holger Gies , Michael M. Scherer

The four-dimensional gauge group of general relativity corresponds to arbitrary coordinate transformations on a four-manifold. Theories of gravity with a dynamical structure remarkably like Einstein's theory can be obtained on the basis of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Julian Barbour , Niall O Murchadha

We extensively study the ultraviolet quantum properties of a nonlocal action for gravity nonminimally coupled to matter. The theory unifies matter and gravity in an action principle such that all the classical solutions of Einstein's theory…

High Energy Physics - Theory · Physics 2024-11-26 Gianluca Calcagni , Breno L. Giacchini , Leonardo Modesto , Tibério de Paula Netto , Lesław Rachwał

The quantization of Einstein-Maxwell theory with a cosmological constant is considered. We obtain all logarithmically divergent terms in the one-loop effective action that involve only the background electromagnetic field. This includes…

High Energy Physics - Theory · Physics 2009-11-06 David J. Toms

Unimodular Gravity (UG) is a restricted version of General Relativity (GR) in which the determinant of the metric is a fixed function and the field equations are given by the trace-free part of the full Einstein equations. The background…

General Relativity and Quantum Cosmology · Physics 2016-09-02 Abhishek Basak , Ophélia Fabre , S. Shankaranarayanan

In this paper we discuss the universality of the renormalization of the gauge coupling constant in the quantum electrodynamics coupled to the Einstein's gravity in the framework of effective field theory in an arbitrary gauge. We observe…

High Energy Physics - Theory · Physics 2021-12-15 L. Ibiapina Bevilaqua , A. C. Lehum , Huan Souza

The scaling properties of quantum gravity are discussed by employing a class of proper-time regulators in the functional flow equation for the conformal factor within the formalism of the background field method. Renormalization group…

High Energy Physics - Theory · Physics 2013-12-10 Alfio Bonanno , Filippo Guarnieri

We formulate a renormalizable quantum gravity in $2+\epsilon$ dimensions by generalizing the nonlinear sigma model approach to string theory. We find that the theory possesses the ultraviolet stable fixed point if the central charge of the…

High Energy Physics - Theory · Physics 2009-10-22 Hikaru Kawai , Yoshihisa Kitazawa , Masao Ninomiya

We explore asymptotic safety of gravity-matter systems, discovering indications for a near-perturbative nature of these systems in the ultraviolet. Our results are based on the dynamical emergence of effective universality at the…

High Energy Physics - Theory · Physics 2019-04-19 Astrid Eichhorn , Stefan Lippoldt , Jan M. Pawlowski , Manuel Reichert , Marc Schiffer

Unimodular gravity is a compelling modified theory of gravity that offers a natural solution to the cosmological constant problem. However, for unimodular gravity to be considered a viable theory of gravity, one has to show that it has a…

General Relativity and Quantum Cosmology · Physics 2024-05-10 J. E. Herrera , Y. Bonder
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