scholarly journals Graviton Propagator from Background-Independent Quantum Gravity

2006 ◽  
Vol 97 (15) ◽  
Author(s):  
Carlo Rovelli
Keyword(s):  
Quantum Gravity ◽  
Graviton Propagator

scholarly journals Renormalizable and Unitary Model of Quantum Gravity

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1334
Author(s):  
S. A. Larin
Keyword(s):  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Relativistic Quantum ◽  
Dimensional Regularization ◽  
Graviton Propagator ◽  
Unitary Model ◽  
Theory Of Gravity ◽  
Made In

We consider R + R 2 relativistic quantum gravity with the action where all possible terms quadratic in the curvature tensor are added to the Einstein-Hilbert term. This model was shown to be renormalizable in the work by K.S. Stelle. In this paper, we demonstrate that the R + R 2 model is also unitary contrary to the statements made in the literature, in particular in the work by Stelle. New expressions for the R + R 2 Lagrangian within dimensional regularization and the graviton propagator are derived. We demonstrate that the R + R 2 model is a good candidate for the fundamental quantum theory of gravity.

scholarly journals TENSORIAL STRUCTURE OF THE LQG GRAVITON PROPAGATOR

2008 ◽  
Vol 23 (08) ◽  
pp. 1209-1213 ◽  
Author(s):  
EMANUELE ALESCI
Keyword(s):  
Asymptotic Behavior ◽  
Quantum Gravity ◽  
Loop Quantum Gravity ◽  
Long Distance ◽  
Graviton Propagator ◽  
Distance Limit

We review the construction of the tensorial structure of the graviton propagator in the context of loop quantum gravity and spinfoam formalism. The main result of this analysis is that applying the same strategy used to compute the diagonal terms, the Barrett-Crane vertex is unable to yield the correct propagator in the long distance limit. The problem is in the intertwiner-independence of the Barrett-Crane vertex. We also review the asymptotic behavior of an alternative vertex that is able to give the correct propagator.

scholarly journals Fourth-derivative relativistic quantum gravity

2018 ◽  
Vol 191 ◽  
pp. 07002 ◽  
Author(s):  
S.A. Larin
Keyword(s):  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Relativistic Quantum ◽  
Dimensional Regularization ◽  
Quantum Theory Of Gravitation ◽  
Graviton Propagator ◽  
Fourth Derivative ◽  
Theory Of Gravitation

We consider relativistic quantum gravity with the action including terms quadratic in the curvature tensor. This model is known to be renormalizable. We demonstrate that the model is also unitary. New expressions for the corresponding Lagrangian and the graviton propagator within dimensional regularization are derived. We argue that the considered model is the proper candidate for the fundamental quantum theory of gravitation.

scholarly journals Reconstructing the graviton

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Alfio Bonanno ◽  
Tobias Denz ◽  
Jan M. Pawlowski ◽  
Manuel Reichert
Keyword(s):  
Quantum Gravity ◽  
Spectral Function ◽  
Cross Sections ◽  
Graviton Propagator ◽  
Dynamical Fluctuation

We reconstruct the Lorentzian graviton propagator in asymptotically safe quantum gravity from Euclidean data. The reconstruction is applied to both the dynamical fluctuation graviton and the background graviton propagator. We prove that the spectral function of the latter necessarily has negative parts similar to, and for the same reasons, as the gluon spectral function. In turn, the spectral function of the dynamical graviton is positive. We argue that the latter enters cross sections and other observables in asymptotically safe quantum gravity. Hence, its positivity may hint at the unitarity of asymptotically safe quantum gravity.

scholarly journals Higher-derivative relativistic quantum gravity

2018 ◽  
Vol 33 (05) ◽  
pp. 1850028 ◽  
Author(s):  
S. A. Larin
Keyword(s):  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Relativistic Quantum ◽  
Dimensional Regularization ◽  
Quantum Theory Of Gravitation ◽  
Higher Derivative ◽  
Graviton Propagator ◽  
Theory Of Gravitation

Relativistic quantum gravity with the action including terms quadratic in the curvature tensor is analyzed. We derive new expressions for the corresponding Lagrangian and the graviton propagator within dimensional regularization. We argue that the considered model is a good candidate for the fundamental quantum theory of gravitation.

scholarly journals Graviton propagator in loop quantum gravity

2006 ◽  
Vol 23 (23) ◽  
pp. 6989-7028 ◽  
Author(s):  
Eugenio Bianchi ◽  
Leonardo Modesto ◽  
Carlo Rovelli ◽  
Simone Speziale
Keyword(s):  
Quantum Gravity ◽  
Loop Quantum Gravity ◽  
Graviton Propagator

COMPARING LQG WITH THE LINEARIZED THEORY

2008 ◽  
Vol 23 (08) ◽  
pp. 1200-1208 ◽  
Author(s):  
ELENA MAGLIARO ◽  
CLAUDIO PERINI
Keyword(s):  
Quantum Gravity ◽  
Field Theories ◽  
General Boundary ◽  
Graviton Propagator ◽  
Linearized Theory ◽  
Perturbative Quantum ◽  
The One ◽  
General Boundary Formulation

We illustrate the conceptual scenario of the general boundary formulation for field theories and present a brief description of the calculus of graviton propagator in the context of LQG. Then we analyze the possibility of comparing this result with the graviton propagator in perturbative quantum gravity. For this purpose we demonstrate the compatibility of harmonic and radial gauge; it allows to simultaneously impose both gauges and to obtain an expression for the propagator comparable with the one provided by LQG.

Topology knots and hierarchy problem

2019 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
Quantum Theory ◽  
String Theory ◽  
Quantum Gravity ◽  
Dimensional Space ◽  
Space Time ◽  
Elementary Particles ◽  
Hierarchy Problem ◽  
Topological Quantum ◽  
Dimensional Space Time ◽  
New Formula

Many approaches to quantum gravity consider the revision of the space-time geometry and the structure of elementary particles. One of the main candidates is string theory. It is possible that this theory will be able to describe the problem of hierarchy, provided that there is an appropriate Calabi-Yau geometry. In this paper we will proceed from the traditional view on the structure of elementary particles in the usual four-dimensional space-time. The only condition is that quarks and leptons should have a common emerging structure. When a new formula for the mass of the hierarchy is obtained, this structure arises from topological quantum theory and a suitable choice of dimensional units.

Braking effect in quantum gravity

2020 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
Quantum Gravity

Braking effect in quantum gravity

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