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Related papers: Dynamics for a 2-vertex Quantum Gravity Model

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This is a review paper about one of the approaches to unify Quantum Mechanics and the theory of General Relativity. Starting from the pioneer work of Regge and Penrose other scientists have constructed state sum models, as Feymann path…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Lorente

We derive an intuitive and novel method to represent nodes in a graph with special unitary operators, or quantum operators, which does not require parameter training and is competitive with classical methods on scoring similarity between…

Quantum Physics · Physics 2024-07-22 Andrew Vlasic , Salvador Aguinaga

We study the notion of volume and its dynamics in the loop-quantum-gravity truncation known as the two-vertex model. We also show that its U(N)-symmetry reduction provides the old effective dynamics of loop quantum cosmology with an…

General Relativity and Quantum Cosmology · Physics 2024-06-17 Álvaro Cendal , Iñaki Garay , Luis J. Garay

We introduce a new operator representing the three-dimensional scalar curvature in loop quantum gravity. The operator is constructed by writing the Ricci scalar classically as a function of the Ashtekar variables and regularizing the…

General Relativity and Quantum Cosmology · Physics 2023-04-04 Ilkka Mäkinen

We give a standard introduction to loop quantum gravity, from the ADM variables to spin network states. We include a discussion on quantum geometry on a fixed graph and its relation to a discrete approximation of general relativity.

General Relativity and Quantum Cosmology · Physics 2010-09-21 Pietro Doná , Simone Speziale

I discuss the role played by the spin-network basis and recoupling theory (in its graphical tangle-theoretic formulation) and their use for performing explicit calculations in loop quantum gravity. In particular, I show that recoupling…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Roberto De Pietri

In canonical quantum gravity, the presence of spatial boundaries naturally leads to a boundary quantum states, representing quantum boundary conditions for the bulk fields. As a consequence, quantum states of the bulk geometry needs to be…

General Relativity and Quantum Cosmology · Physics 2021-08-11 Qian Chen , Etera R. Livine

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

In the context of the quest for a holographic formulation of quantum gravity, we investigate the basic boundary theory structure for loop quantum gravity. In 3+1 space-time dimensions, the boundary theory lives on the 2+1-dimensional…

High Energy Physics - Theory · Physics 2021-01-20 Etera R. Livine

The kinematics of loop gravity can be given a manifestly Lorentz-covariant formulation: the conventional SU(2)-spin-network Hilbert space can be mapped to a space K of SL(2,C) functions, where Lorentz covariance is manifest. K can be…

General Relativity and Quantum Cosmology · Physics 2011-05-25 Carlo Rovelli , Simone Speziale

We consider the statics and dynamics of distinguishable spin-1/2 systems on an arbitrary graph G with N vertices. In particular, we consider systems of quantum spins evolving according to one of two hamiltonians: (i) the XY hamiltonian…

Quantum Physics · Physics 2007-05-23 Tobias J. Osborne

The graphical calculus method is generalized to study the relation between covariant and canonical dynamics of loop quantum gravity. On one hand, a graphical derivation of the partition function of the generalized Euclidean…

General Relativity and Quantum Cosmology · Physics 2021-08-17 Jinsong Yang , Cong Zhang , Yongge Ma

We develop a worldline approach to quantum gravity in D=4. Using the background field method we consider the covariantly gauge fixed Einstein-Hilbert action with cosmological constant, and find a worldline representation of the differential…

High Energy Physics - Theory · Physics 2013-06-25 Fiorenzo Bastianelli , Roberto Bonezzi

An anomaly-free operator corresponding to the Wheeler-DeWitt constraint of Lorentzian, four-dimensional, canonical, non-perturbative vacuum gravity is constructed in the continuum. This operator is entirely free of factor ordering…

General Relativity and Quantum Cosmology · Physics 2008-11-26 T. Thiemann

We investigate the geometry of the space of N-valent SU(2)-intertwiners. We propose a new set of holomorphic operators acting on this space and a new set of coherent states which are covariant under U(N) transformations. These states are…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Laurent Freidel , Etera R. Livine

We define supersymmetric spin networks, which provide a complete set of gauge invariant states for supergravity and supersymmetric gauge theories. The particular case of Osp(1/2) is studied in detail and applied to the non-perturbative…

High Energy Physics - Theory · Physics 2009-10-31 Yi Ling , Lee Smolin

Utilizing the previously established general formalism for quantum symmetry reduction in the framework of loop quantum gravity the spectrum of the area operator acting on spherically symmetric states in 4 dimensional pure gravity is…

High Energy Physics - Theory · Physics 2009-10-31 M. Bojowald , H. A. Kastrup

Motivated by the idea that, in the background-independent framework of a Quantum Theory of Gravity, entanglement is expected to play a key role in the reconstruction of spacetime geometry, we investigate the possibility of using the…

General Relativity and Quantum Cosmology · Physics 2017-03-21 Fabio M. Mele

In recent twenty years, loop quantum gravity, a background independent approach to unify general relativity and quantum mechanics, has been widely investigated. We consider the quantum dynamics of a real massless scalar field coupled to…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Muxin Han , Yongge Ma

We introduce a new technique for dealing with the matrix elements of the Hamiltonian operator in loop quantum gravity, based on the use of intertwiners projected on coherent states of angular momentum. We give explicit expressions for the…

General Relativity and Quantum Cosmology · Physics 2016-10-26 Emanuele Alesci , Jerzy Lewandowski , Ilkka Mäkinen