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Related papers: Dynamics of loop quantum gravity and spin foam mod…

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In this review, the fundamental structure of loop quantum gravity is presented pedagogically. Our main aim is to help non-experts to understand the motivations, basic structures, as well as general results. It may also be beneficial to…

General Relativity and Quantum Cosmology · Physics 2011-05-16 Muxin Han , Weiming Huang , Yongge Ma

We describe the idea of studying quantum gravity by means of dynamical triangulations and give examples of its implementation in 2, 3 and 4 space time dimensions. For $d=2$ we consider the generic hermitian 1-matrix model. We introduce the…

High Energy Physics - Theory · Physics 2007-05-23 C. F. Kristjansen

In this article we introduce a new operator representing the three-dimensional scalar curvature in loop quantum gravity. Our construction does not apply to the entire kinematical Hilbert space of loop quantum gravity; instead, the operator…

General Relativity and Quantum Cosmology · Physics 2023-06-02 Jerzy Lewandowski , Ilkka Mäkinen

The discrepancy between the results of covariant and non-covariant one-loop calculations for higher-spin fields in quantum cosmology is analyzed. A detailed mode-by-mode study of perturbative quantum gravity about a flat Euclidean…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Giampiero Esposito , Alexander Yu. Kamenshchik , Igor V. Mishakov , Giuseppe Pollifrone

Loop quantum gravity is a mature theory. To proceed to explicit calculations in cosmology, it is necessary to make assumptions and simplifications based on the symmetries of the cosmological setting. Symmetry reduction is especially…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Aurélien Barrau , Boris Bolliet

This work concerns a new reformulation of quantum geometrodynamics, which allows to overcome a fundamental ambiguity contained in the canonical approach to quantum gravity: the possibility of performing a (3+1)-slicing of space-time, when…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Simone Mercuri , Giovanni Montani

A functional calculus on the space of (generalized) connections was recently introduced without any reference to a background metric. It is used to continue the exploration of the quantum Riemannian geometry. Operators corresponding to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Abhay Ashtekar , Jerzy Lewandowski

We compute the leading order of the three-point function in loop quantum gravity, using the vertex expansion of the Euclidean version of the new spin foam dynamics, in the region of gamma<1. We find results consistent with Regge calculus in…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Carlo Rovelli , Mingyi Zhang

In this paper, I investigate the possible quantization, in the context of LQG, of three dimensional gravity in the case of positive cosmological constant {\Lambda} and try to make contact with alternative quantization approaches already…

General Relativity and Quantum Cosmology · Physics 2012-08-15 Daniele Pranzetti

In this paper, we study the discrete classical phase space of loop gravity, which is expressed in terms of the holonomy-flux variables, and show how it is related to the continuous phase space of general relativity. In particular, we prove…

General Relativity and Quantum Cosmology · Physics 2013-04-04 Laurent Freidel , Marc Geiller , Jonathan Ziprick

In loop quantum gravity we now have a clear picture of the quantum geometry of space, thanks in part to the theory of spin networks. The concept of `spin foam' is intended to serve as a similar picture for the quantum geometry of spacetime.…

General Relativity and Quantum Cosmology · Physics 2015-02-13 John C. Baez

As a canonical and generally covariant gauge theory, loop quantum gravity requires special techniques to derive effective actions or equations. If the proper constructions are taken into account, the theory, in spite of considerable…

General Relativity and Quantum Cosmology · Physics 2013-08-02 Martin Bojowald

We report on the numerical analysis of the area correlations in spin foam gravity on a single 4-simplex considered by Rovelli in PRL 97 (2006) 151301. We compare the asymptotics and confirm the inverse squared distance leading behaviour at…

General Relativity and Quantum Cosmology · Physics 2009-01-16 J. Daniel Christensen , Etera R. Livine , Simone Speziale

We review and systematize recent attempts to canonically quantize general relativity in 2+1 dimensions, defined on space-times $\R\times\Sigma^g$, where $\Sigma^g$ is a compact Riemann surface of genus $g$. The emphasis is on quantizations…

General Relativity and Quantum Cosmology · Physics 2010-11-01 R. Loll

In the context of canonical quantum gravity, we study an alternative real quantisation scheme, which is arising by relating simpler Riemannian quantum theory to the more complicated physical Lorentzian theory - the generalised Wick…

General Relativity and Quantum Cosmology · Physics 2009-11-10 B. Hartmann , J. Wisniewski

With approaching quantum/noncommutative models for the deep microscopic spacetime in mind, and inspired by our recent picture of the (projective) Hilbert space as the model of physical space behind basic quantum mechanics, we reformulate…

Quantum Physics · Physics 2021-01-13 Chuan Sheng Chew , Otto C. W. Kong , Jason Payne

The new information-theoretic Process Physics has shown that space is a quantum foam system with gravity being, in effect, an inhomogeneous in-flow of the quantum foam into matter. The theory predicts that absolute motion with respect to…

General Physics · Physics 2010-07-14 Reginald T. Cahill

A potentially powerful approach to quantum gravity has been developed over the last few years under the name of Causal Dynamical Triangulations. Numerical simulations have given very interesting results in the cases of two, three and four…

General Relativity and Quantum Cosmology · Physics 2007-09-05 Dario Benedetti

This paper is twofold. First of all a complete unified picture of $n$-dimensional quantum gravity is proposed in the following sense: In spin foam models of quantum gravity the evaluation of spin networks play a very important role. These…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. Manuel Garcia-Islas

Based on a recent purely geometric construction of observables for the spatial diffeomorphism constraint, we propose two distinct quantum reductions to spherical symmetry within full 3+1-dimensional loop quantum gravity. The construction of…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Norbert Bodendorfer , Jerzy Lewandowski , Jedrzej Świeżewski