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Related papers: Area Propagator and Boosted Spin Networks in Loop …

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We discuss the relation between coarse-graining and the holographic principle in the framework of loop quantum gravity and ask the following question: when we coarse-grain arbitrary spin network states of quantum geometry, are we…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Etera R. Livine

A new link between tetrahedra and the group SU(2) is pointed out: by associating to each face of a tetrahedron an irreducible unitary SU(2) representation and by imposing that the faces close, the concept of quantum tetrahedron is seen to…

General Relativity and Quantum Cosmology · Physics 2009-10-30 A. Barbieri

The spin network simulator model represents a bridge between (generalised) circuit schemes for standard quantum computation and approaches based on notions from Topological Quantum Field Theories (TQFTs). The key tool is provided by the…

Quantum Physics · Physics 2009-01-06 Annalisa Marzuoli , Mario Rasetti

We construct a class of spin foam models describing matter coupled to gravity, such that the gravitational sector is described by the unitary irreducible representations of the appropriate symmetry group, while the matter sector is…

High Energy Physics - Theory · Physics 2009-01-16 A. Mikovic

In this article we propose a new construction of the spatial scalar curvature operator in (1+3)-dimensional LQG based on the twisted geometry. The starting point of the construction is to express the holonomy of the spin connection on a…

General Relativity and Quantum Cosmology · Physics 2024-12-02 Gaoping Long , Hongguang Liu

Quantum networks are often modelled using Schroedinger operators on metric graphs. To give meaning to such models one has to know how to interpret the boundary conditions which match the wave functions at the graph vertices. In this article…

Mathematical Physics · Physics 2009-11-13 Pavel Exner , Olaf Post

The phenomenology for the deep spatial geometry of loop quantum gravity is discussed. In the context of a simple model of an atom of space, it is shown how purely combinatorial structures can affect observations. The angle operator is used…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Seth A. Major

The fermion propagator is derived in detail from the model of fermion coupled to loop quantum gravity. As an ingredient of the propagator, the vacuum state is defined as the ground state of some effective fermion Hamiltonian under the…

General Relativity and Quantum Cosmology · Physics 2023-11-14 Cong Zhang , Hongguang Liu , Muxin Han

We review and extend the recently proposed model of combinatorial quantum gravity. Contrary to previous discrete approaches, this model is defined on (regular) random graphs and is driven by a purely combinatorial version of Ricci…

High Energy Physics - Theory · Physics 2020-01-08 C. Kelly , C. A. Trugenberger

We describe a deformation of the observable algebra of quantum gravity in which the loop algebra is extended to framed loops. This allows an alternative nonperturbative quantization which is suitable for describing a phase of quantum…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Seth Major , Lee Smolin

We study the symplectic reduction of the phase space of two twistors to the cotangent bundle of the Lorentz group. We provide expressions for the Lorentz generators and group elements in terms of the spinors defining the twistors. We use…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Etera R. Livine , Simone Speziale , Johannes Tambornino

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

We discuss the action of the configuration operators of loop quantum gravity. In particular, we derive the generalised eigenbasis for the Wilson loop operator and show that the transformation between this basis and the spin-network basis is…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Matthias Arnsdorf

We investigate the quantum geometry of $2d$ surface $S$ bounding the Cauchy slices of 4d gravitational system. We investigate in detail and for the first time the symplectic current that naturally arises boundary term in the first order…

General Relativity and Quantum Cosmology · Physics 2015-07-10 Laurent Freidel , Alejandro Perez

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected to project quantum states of the geometry…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Federico Mattei , Carlo Rovelli , Simone Speziale , Massimo Testa

We propose an unified approach to loop quantum gravity and Fedosov quantization of gravity following the geometry of double spacetime fibrations and their quantum deformations. There are considered pseudo-Riemannian manifolds enabled with…

General Relativity and Quantum Cosmology · Physics 2009-11-21 Sergiu I. Vacaru

We study the holographic properties of a class of quantum geometry states characterized by a superposition of discrete geometric data, in the form of generalised tensor networks. This class specifically includes spin networks, the kinematic…

Quantum Physics · Physics 2024-02-28 Eugenia Colafranceschi , Simon Langenscheidt , Daniele Oriti

In the loop quantum gravity framework, spin network states carry entanglement between quantum excitations of the geometry at different space points. This intertwiner entanglement is gauge-invariant and comes from quantum superposition of…

General Relativity and Quantum Cosmology · Physics 2022-10-19 Qian Chen , Etera R. Livine

Recent attempts to resolve the ambiguity in the loop quantum gravity description of the quantization of area has led to the idea that j=1 edges of spin-networks dominate in their contribution to black hole areas as opposed to j=1/2 which…

General Relativity and Quantum Cosmology · Physics 2016-11-09 John Swain

The search for a quantum theory of gravity is one of the major challenges facing theoretical physics today. While no complete theory exists, a promising avenue of research is the loop quantum gravity approach. In this approach, quantum…

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