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Related papers: Modified constraint algebra in loop quantum gravit…

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It is shown that introducing the quantum effects using deBroglie--Bohm theory in the canonical formulation of gravity would change the constraints algebra. The new algebra is derived and shown that it is the clear projection of general…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Ali Shojai , Fatimah Shojai

In this work a loop quantum corrected model is obtained for spherically symmetric space-times in the vacuum. This effective model is derived by the use of the path integral method, previously employed in several models of Loop Quantum…

General Relativity and Quantum Cosmology · Physics 2026-05-21 Juan Carlos Del Águila , Hugo A. Morales

To ask a question about a black hole in quantum gravity, one must restrict initial or boundary data to ensure that a black hole is actually present. For two-dimensional dilaton gravity, and probably a much wider class of theories, I show…

High Energy Physics - Theory · Physics 2010-04-28 S. Carlip

Emergent modified gravity provides a covariant, effective framework for obtaining spherically symmetric black hole solutions in models of loop quantum gravity with scale-dependent holonomy modifications. Exact solutions for vacuum black…

General Relativity and Quantum Cosmology · Physics 2024-07-18 Idrus Husin Belfaqih , Martin Bojowald , Suddhasattwa Brahma , Erick I. Duque

Loop quantum gravity introduces two characteristic modifications in the classical constraints of general relativity: the holonomy and inverse-triad corrections. In this paper, a systematic construction of anomaly-free effective constraints…

General Relativity and Quantum Cosmology · Physics 2022-08-12 Asier Alonso-Bardaji , David Brizuela

We quantize spherically symmetric electrovacuum gravity. The algebra of Hamiltonian constraints can be made Abelian via a rescaling and linear combination with the diffeomorphism constraint. As a result the constraint algebra is a true Lie…

General Relativity and Quantum Cosmology · Physics 2015-04-16 Rodolfo Gambini , Esteban Mato Capurro , Jorge Pullin

The dynamical systems invariant under gauge transformations with higher order time derivatives of the gauge parameter are considered from the Hamiltonian point of view. We investigate the consequences of the basic requirements that the…

High Energy Physics - Theory · Physics 2009-11-13 M. N. Stoilov

We study a class of theories in which space-time is treated classically, while interacting with quantum fields. These circumvent various no-go theorems and the pathologies of semi-classical gravity, by being linear in the density matrix and…

High Energy Physics - Theory · Physics 2022-02-15 Jonathan Oppenheim , Zachary Weller-Davies

We use the mathematical framework of loop quantum gravity (LQG) to study the quantization of three dimensional (Riemannian) gravity with positive cosmological constant (Lambda>0). We show that the usual regularization techniques (successful…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Alejandro Perez , Daniele Pranzetti

We present new second derivative, generally covariant theories of gravity for spherically symmetric spacetimes (general covariance is in the $t-r$ plane) belonging to the class where the spherically symmetric Einstein-Hilbert theory is…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Rakesh Tibrewala

Most of the potential physical effects of loop quantum gravity have been derived in effective models that modify the constraints of canonical general relativity in specific forms. Emergent modified gravity evaluates important conditions…

General Relativity and Quantum Cosmology · Physics 2025-05-01 Idrus Husin Belfaqih , Martin Bojowald , Suddhasattwa Brahma , Erick I. Duque

A fully consistent linear perturbation theory for cosmology is derived in the presence of quantum corrections as they are suggested by properties of inverse volume operators in loop quantum gravity. The underlying constraints present a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Golam Mortuza Hossain , Mikhail Kagan , S. Shankaranarayanan

The existence of black holes is a central prediction of general relativity and thus serves as a basic consistency test for modified theories of gravity. In spherical symmetry, only two classes of dynamic solutions are compatible with the…

General Relativity and Quantum Cosmology · Physics 2022-03-01 Sebastian Murk

In the Hamiltonian formulation of general relativity, Einstein's equation is replaced by a set of four constraints. Classically, the constraints can be identified with the generators of the hypersurface-deformation Lie algebroid (HDA) that…

High Energy Physics - Theory · Physics 2018-08-08 Martin Bojowald , Suddhasattwa Brahma , Umut Buyukcam , Michele Ronco

In canonical gravity, covariance is implemented by brackets of hypersurface-deformation generators forming a Lie algebroid. Lie algebroid morphisms therefore allow one to relate different versions of the brackets that correspond to the same…

General Relativity and Quantum Cosmology · Physics 2016-11-15 Martin Bojowald , Suddhasattwa Brahma , Umut Buyukcam , Fabio D'Ambrosio

We study time-reversal and parity ---on the physical manifold and in internal space--- in covariant loop gravity. We consider a minor modification of the Holst action which makes it transform coherently under such transformations. The…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Carlo Rovelli , Edward Wilson-Ewing

We derive a new constraint algebra for a Hamiltonian formulation of the Teleparallel Equivalent of General Relativity treated as a theory of cotetrad fields on a spacetime. The algebra turns out to be closed.

General Relativity and Quantum Cosmology · Physics 2021-06-22 Andrzej Okolow

An explicit example is found showing how a modified theory of gravity can be constrained with the ringdown signals from merger of binary black holes. This has been made possible by the fact that the modified gravitational theory considered…

General Relativity and Quantum Cosmology · Physics 2019-10-23 Jiahui Bao , Changfu Shi , Haitian Wang , Jian-dong Zhang , Yiming Hu , Jianwei Mei , Jun Luo

Spherically symmetric models of loop quantum gravity have been studied recently by different methods that aim to deal with structure functions in the usual constraint algebra of gravitational systems. As noticed by Gambini and Pullin, a…

General Relativity and Quantum Cosmology · Physics 2015-09-09 Martin Bojowald , Suddhasattwa Brahma , Juan D. Reyes

We analyze the thermodynamical properties of black holes in a modified theory of gravity, which was initially proposed to obtain correct dynamics of galaxies and galaxy clusters without dark matter. The thermodynamics of non-rotating and…

General Relativity and Quantum Cosmology · Physics 2016-05-20 Jonas R. Mureika , John W. Moffat , Mir Faizal