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Related papers: New length operator for loop quantum gravity

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Two sets of spatially diffeomorphism invariant operators are constructed in the loop representation formulation of quantum gravity. This is done by coupling general relativity to an anti- symmetric tensor gauge field and using that field to…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Lee Smolin

We analyze the different ways to define the energy operator in geometric theories of quantum mechanics. In some formulations the operator contains the scalar curvature as a multiplicative term. We show that such term can be canceled or…

Mathematical Physics · Physics 2014-08-27 Carlos Tejero Prieto , Raffaele Vitolo

We study the spectrum of the length and area operators in Lorentzian loop quantum gravity, in 2+1 spacetime dimensions. We find that the spectrum of spacelike intervals is continuous, whereas the spectrum of timelike intervals is discrete.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Laurent Freidel , Etera R. Livine , Carlo Rovelli

The 4-dimensional metric $f(\R)$ theories of gravity are cast into connection-dynamical formalism with real $\SU(2)$-connections as configuration variables. Through this formalism, the classical metric $f(\R)$ theories are quantized by…

General Relativity and Quantum Cosmology · Physics 2011-05-09 Xiangdong Zhang , Yongge Ma

In loop quantum gravity in the connection representation, the quantum configuration space $\bar{\mathcal{A}/\mathcal{G}}$, which is a compact space, is much larger than the classical configuration space $\mathcal{A}/% \mathcal{G}$ of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Andreas Doering , Hans F. de Groote

After motivating why the study of asymptotically flat spaces is important in loop quantum gravity, we review the extension of the standard framework of this theory to the asymptotically flat sector based on the GNS construction. In…

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

In quantum gravity it is generally thought that a modified commutator of the form $[{\hat x}, {\hat p}] = i \hbar (1 + \beta p^2)$ is sufficient to give rise to a minimum length scale. We test this assumption and find that different pairs…

General Relativity and Quantum Cosmology · Physics 2020-05-19 Michael Bishop , Jaeyeong Lee , Douglas Singleton

The properties of the Volume operator in Loop Quantum Gravity, as constructed by Ashtekar and Lewandowski, are analyzed for the first time at generic vertices of valence greater than four. The present analysis benefits from the general…

General Relativity and Quantum Cosmology · Physics 2010-11-26 Johannes Brunnemann , David Rideout

We describe preliminary results of a detailed numerical analysis of the volume operator as formulated by Ashtekar and Lewandowski. Due to a simplified explicit expression for its matrix elements, it is possible for the first time to treat…

General Relativity and Quantum Cosmology · Physics 2009-11-11 J. Brunnemann , D. Rideout

In this paper we introduce the concept of quadratic operator perspective for a continuous function {\Phi} defined on the positive semi-axis of real numbers. This generalize the quadratic weighted operator geometric mean and the quadratic…

Functional Analysis · Mathematics 2016-09-29 Silvestru Sever Dragomir

We outline how the Wald entropy formula naturally arises in loop quantum gravity based on recently introduced dimension-independent connection variables. The key observation is that in a loop quantization of a generalized gravity theory,…

General Relativity and Quantum Cosmology · Physics 2014-11-25 Norbert Bodendorfer , Yasha Neiman

In this paper, we introduce the $f-$operator radius of Hilbert space operators as a generalization of the Euclidean operator radius and the $q-$operator radius. Properties of the newly defined radius are discussed, emphasizing how it…

Functional Analysis · Mathematics 2022-11-02 Mohammad W. Alomari , Mohammad Sababheh , Cristian Conde , Hamid Reza Moradi

We consider the coupling between massive and spinning particles and three dimensional gravity. This allows us to construct geometric operators (distances between particles) as Dirac observables. We quantize the system a la loop quantum…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Karim Noui , Alejandro Perez

Since there are quantization ambiguities in constructing the Hamiltonian constraint operator in isotropic loop quantum cosmology, it is crucial to check whether the key features of loop quantum cosmology are robust against the ambiguities.…

General Relativity and Quantum Cosmology · Physics 2010-04-14 Jinsong Yang , You Ding , Yongge Ma

To adopt a practical method to calculate the action of geometrical operators on quantum states is a crucial task in loop quantum gravity. In the series of papers, we will introduce a graphical method, developed by Yutsis and Brink, to loop…

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

Motivated by both concepts of R.J. Adler's recent work on utilizing Clifford algebra as the linear line element $ds = \left\langle \gamma_\mu \right\rangle dX^\mu $, and the fermionization of the cylindrical worldsheet Polyakov action, we…

High Energy Physics - Theory · Physics 2016-04-27 Hsu-Wen Chiang , Yao-Chieh Hu , Pisin Chen

It is often inevitable to introduce an indefinite-metric space in quantum field theory. There is a problem to determine the metric structure of a given representation space of field operators. We show the systematic method to determine such…

Operator Algebras · Mathematics 2007-05-23 Katsunori Kawamura

The problem of defining time (or phase) operator for three-dimensional harmonic oscillator has been analyzed. A new formula for this operator has been derived. The results have been used to demonstrate a possibility of representing…

Quantum Physics · Physics 2009-11-07 Pavel Kundrat , Milos V. Lokajicek

Important characteristics of the loop approach to quantum gravity are a specific choice of the algebra A of observables and of a representation of A on a measure space over the space of generalized connections. This representation is…

General Relativity and Quantum Cosmology · Physics 2011-01-27 Hanno Sahlmann

A quantum theory of gravity is described in the case of a positive cosmological constant in 3+1 dimensions. Both old and new results are described, which support the case that loop quantum gravity provides a satisfactory quantum theory of…

High Energy Physics - Theory · Physics 2007-05-23 Lee Smolin
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