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Related papers: Loop representation of Quantum Gravity

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We define solvable quantum mechanical systems on a Hilbert space spanned by bipartite ribbon graphs with a fixed number of edges. The Hilbert space is also an associative algebra, where the product is derived from permutation group…

High Energy Physics - Theory · Physics 2023-07-17 Joseph Ben Geloun , Sanjaye Ramgoolam

The questions of describing observables and observation in quantum gravity appear to be centrally important to its physics. A relational approach holds significant promise, and a classification of different types of relational observables…

High Energy Physics - Theory · Physics 2025-06-13 Steven B. Giddings

Ever since the pioneer works of Bekenstein and Hawking, black hole entropy has been known to have a quantum origin. Furthermore, it has long been argued by Bekenstein that entropy should be quantized in discrete (equidistant) steps given…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alejandro Corichi , Jacobo Diaz-Polo , Enrique Fernandez-Borja

We provide arguments indicating that the semiclassical Einstein equations follow from quantum relative entropy and its proportionality to an area variation. Using modular theory, we establish that the relative entropy between the vacuum…

High Energy Physics - Theory · Physics 2026-03-04 Philipp Dorau , Albert Much

In this article we explore the origin of black hole thermodynamics using semiclassical states in loop quantum gravity. We re-examine the case of entropy using a density matrix for a coherent state and describe correlations across the…

General Relativity and Quantum Cosmology · Physics 2013-02-19 Arundhati Dasgupta

We compute numerically the time evolution of simple semiclassical states describing homogeneous and isotropic spatial geometries in quantum-reduced loop gravity under a deparametrized formulation of the dynamics, in which a reference matter…

General Relativity and Quantum Cosmology · Physics 2026-04-02 Ilkka Mäkinen

We construct a state in the loop quantum gravity theory with zero cosmological constant, which should correspond to the flat spacetime vacuum solution. This is done by defining the loop transform coefficients of a flat connection…

General Relativity and Quantum Cosmology · Physics 2009-01-16 A. Mikovic

Quantum coherence and distributed correlations among subparties are often considered as separate, although operationally linked to each other, properties of a quantum state. Here, we propose a measure able to quantify the contributions…

Quantum Physics · Physics 2018-12-11 Gian Luca Giorgi , Roberta Zambrini

We present the construction of a physical Hamiltonian operator in the deparametrized model of loop quantum gravity coupled to a free scalar field. This construction is based on the use of the recently introduced curvature operator, and on…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Emanuele Alesci , Mehdi Assanioussi , Jerzy Lewandowski , Ilkka Mäkinen

This is the second paper in the series to introduce a graphical method to loop quantum gravity. We employ the graphical method as a powerful tool to calculate the actions of the Euclidean Hamiltonian constraint operator and the so-called…

General Relativity and Quantum Cosmology · Physics 2016-02-25 Jinsong Yang , Yongge Ma

We review a geometric approach to classification and examination of quantum correlations in composite systems. Since quantum information tasks are usually achieved by manipulating spin and alike systems or, in general, systems with a finite…

Quantum Physics · Physics 2019-03-27 A. Sawicki , T. Maciążek , M. Oszmaniec , K. Karnas , K. Kowalczyk-Murynka , M. Kuś

Inspired by ER=EPR conjecture we present a mathematical tool providing a link between quantum entanglement and the geometry of spacetime. We start with the idea of operators in extended Hilbert space which, by definition, has no positive…

High Energy Physics - Theory · Physics 2019-08-30 Grzegorz Plewa

Hilbert spaces in theories of gravity are notoriously subtle due to the Hamiltonian constraints, particularly regarding the inner product. To demystify this subject, we review and extend a collection of ideas in canonical gravity, and…

High Energy Physics - Theory · Physics 2026-05-15 Jesse Held , Henry Maxfield

In this paper we establish the existence of the non-perturbative theory of quantum gravity known as quantum holonomy theory by showing that a Hilbert space representation of the QHD(M) algebra, which is an algebra generated by…

General Relativity and Quantum Cosmology · Physics 2018-09-18 Johannes Aastrup , Jesper M. Grimstrup

The existence of a minimal observable length has long been suggested, in quantum gravity, as well as in string theory. In this context a generalized uncertainty relation has been derived which quantum theoretically describes the minimal…

High Energy Physics - Theory · Physics 2009-07-09 A. Kempf , G. Mangano , R. B. Mann

Spin networks in Loop Quantum Gravity are traditionally described by unitary holonomies corresponding to noiseless transformations. In this work, we extend this framework to incorporate general quantum channels that model effects of…

General Relativity and Quantum Cosmology · Physics 2026-02-13 Bartosz Grygielski , Jakub Mielczarek

Attempts to formulate a quantum theory of gravitation are collectively known as {\it quantum gravity}. Various approaches to quantum gravity such as string theory and loop quantum gravity, as well as black hole physics and doubly special…

High Energy Physics - Theory · Physics 2011-12-25 Ahmed Farag Ali , Saurya Das , Elias C. Vagenas

This introductory review is addressed to beginning researchers. Some of the distinguishing features of loop quantum gravity are illustrated through loop quantum cosmology of FRW models. In particular, these examples illustrate: i) how…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Abhay Ashtekar

We consider a spherical symmetric black hole in the Schwarzschild metric and apply Bohr-Sommerfeld quantization to determine the energy levels. The canonical partition function is then computed and we show that the entropy coincides with…

High Energy Physics - Theory · Physics 2010-11-19 Marco Frasca

It is seen that issues of unitarity raised by the evolution of the wave function in curved spacetime can be resolved by describing the evolution of quantum states in Minkowski tangent space. The treatment adheres closely to the orthodox…

General Relativity and Quantum Cosmology · Physics 2016-03-15 Charles Francis