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We construct in this article a new realization of quantum geometry, which is obtained by quantizing the recently-introduced flux formulation of loop quantum gravity. In this framework, the vacuum is peaked on flat connections, and states…

General Relativity and Quantum Cosmology · Physics 2021-06-18 Benjamin Bahr , Bianca Dittrich , Marc Geiller

The geometric operators of area, volume, and length, depend on a fundamental length l of quantum geometry which is a priori arbitrary rather than equal to the Planck length l_P. The fundamental length l and the Immirzi parameter $\gamma$…

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

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

The newly found conformal decomposition in canonical general relativity is applied to drastically simplify the recently formulated parameter-free construction of spin-gauge variables for gravity. The resulting framework preserves many of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Charles H. -T. Wang

Using Monte Carlo simulations, we compute the integrated emission spectra of black holes in the framework of Loop Quantum Gravity (LQG). The black hole emission rates are governed by the entropy whose value, in recent holographic loop…

General Relativity and Quantum Cosmology · Physics 2015-12-30 Aurelien Barrau , Xiangyu Cao , Karim Noui , Alejandro Perez

The Loop Quantum Gravity (LQG) program is briefly reviewed and one of its main applications, namely the counting of black hole entropy within the framework is considered. In particular, recent results for Planck size black holes are…

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

One of the qualitatively distinct and robust implication of Loop Quantum Gravity (LQG) is the underlying discrete structure. In the cosmological context elucidated by Loop Quantum Cosmology (LQC), this is manifested by the Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Kinjal Banerjee , Ghanashyam Date

Using quadratic spinor techniques we demonstrate that the Immirzi parameter can be expressed as ratio between scalar and pseudo-scalar contributions in the theory and can be interpreted as a measure of how Einstein gravity differs from a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Chung-Hsien Chou , Roh-Suan Tung , Hoi-Lai Yu

The most important problem of fundamental Physics is the quantization of the gravitational field. A main difficulty is the lack of available experimental tests that discriminate among the theories proposed to quantize gravity. Recently,…

High Energy Physics - Theory · Physics 2009-11-10 Jorge Alfaro

Loop Quantum Gravity (LQG) is an attempt to describe the quantum gravity regime. Introducing a non-zero cosmological constant $\Lambda$ in this context has been a withstanding problem. Other approaches, such as Chern-Simons gravity, suggest…

General Relativity and Quantum Cosmology · Physics 2013-07-24 Maite Dupuis , Florian Girelli

We study numerically the first order radiative corrections to the self-energy, in covariant loop quantum gravity. We employ the recently developed 'sl2cfoam-next' spinfoam amplitudes library, and some original numerical methods. We analyze…

General Relativity and Quantum Cosmology · Physics 2022-09-29 Pietropaolo Frisoni , Francesco Gozzini , Francesca Vidotto

The Barbero-Immirzi (BI) parameter is promoted to a field and a canonical analysis is performed when it is coupled with a Nieh-Yan topological invariant. It is shown that, in the effective theory, the BI field is a canonical pseudoscalar…

General Relativity and Quantum Cosmology · Physics 2009-07-24 Gianluca Calcagni , Simone Mercuri

Isolated horizons model equilibrium states of classical black holes. A detailed quantization, starting from a classical phase space restricted to spherically symmetric horizons, exists in the literature and has since been extended to…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Christopher Beetle , Jonathan Engle

The Kodama State for Lorentzian gravity presupposes a particular value for the Immirzi-parameter, namely $\beta=-i$. However, the derivation of black hole entropy in Loop Quantum Gravity suggests that the Immirzi parameter is a fixed value…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Andrew Randono

A genuine notion of black holes can only be obtained in the fundamental framework of quantum gravity resolving the curvature singularities and giving an account of the statistical mechanical, microscopic degrees of freedom able to explain…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Christian Röken

An equidistant spectrum of the horizon area of a quantized black hole does not follow from the correspondence principle or from general statistical arguments. Such a spectrum obtained earlier in loop quantum gravity (LQG) does not comply…

General Relativity and Quantum Cosmology · Physics 2007-05-23 I. B. Khriplovich

Bombagcino investigated the role of Immirzi parameter when promoted to a field in Einstein-Cartan-Holst black hole and they found that the Immirzi field acts similar to the axion field, as both axial pseudo-vector and vectorial torsion…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 Zhi Fu Gao , Biao Peng Li , L. C. Garcia de Andrade

We promote the Immirzi parameter to be a minimally coupled scalar field and we analyzed the Hamiltonian constraints in the framework of Loop Quantum Gravity without the time gauge. Proper SU(2) connections can be defined and a term…

General Relativity and Quantum Cosmology · Physics 2009-11-05 Francesco Cianfrani , Giovanni Montani

We shall here discuss a new spacetime gauge-covariant Lagrangian formulation of General Relativity by means of the Barbero-Immirzi SU(2)-connection on spacetime. To the best of our knowledge the Lagrangian based on SU(2) spacetime fields…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Fatibene , M. Francaviglia , C. Rovelli

We set up a canonical Hamiltonian formulation for a theory of gravity based on a Lagrangian density made up of the Hilbert-Palatini term and, instead of the Holst term, the Nieh-Yan topological density. The resulting set of constraints in…

General Relativity and Quantum Cosmology · Physics 2009-09-02 Ghanashyam Date , Romesh K. Kaul , Sandipan Sengupta