English
Related papers

Related papers: Properties of the Volume Operator in Loop Quantum …

200 papers

We summarize our work on spherically symmetric midi-superspaces in loop quantum gravity. Our approach is based on using inhomogeneous slicings that may penetrate the horizon in case there is one and on a redefinition of the constraints so…

General Relativity and Quantum Cosmology · Physics 2025-05-14 Rodolfo Gambini , Javier Olmedo , Jorge Pullin

The leading quantum correction to Einstein-Hilbert Hamiltonian coming from large volume vacuum isotropic loop quantum cosmology, is independent of quantization ambiguity parameters. It is shown here that this correction can be viewed as…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Golam Mortuza Hossain

We examine Bousso's covariant entropy bound conjecture in the context of radiation filled, spatially flat, Friedmann-Robertson-Walker models. The bound is violated near the big bang. However, the hope has been that quantum gravity effects…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Abhay Ashtekar , Edward Wilson-Ewing

The dissertation deals with noncommutative field theories, namely field theories compatible with the existence of a minimal (quantum gravity) length scale. Two families of quantum spacetime are considered. One is characterized by semisimple…

High Energy Physics - Theory · Physics 2018-11-19 Timothé Poulain

Eigenvalues and eigenfunctions of the volume operator, associated with the symmetric coupling of three SU(2) angular momentum operators, can be analyzed on the basis of a discrete Schroedinger-like equation which provides a semiclassical…

Quantum Physics · Physics 2014-08-27 V. Aquilanti , D. Marinelli , A. Marzuoli

We introduce a notion of residual diffeomorphism covariance in quantum Kantowski-Sachs (KS), describing the interior of a Schwarzschild black hole. We solve for the family of Hamiltonian constraint operators satisfying the associated…

General Relativity and Quantum Cosmology · Physics 2024-01-12 Ian W. Bornhoeft , Rafael G. Dias , Jonathan S. Engle

Let $G$ be a higher rank simple real algebraic group, or more generally, any semisimple real algebraic group with no rank one factors and $X$ the associated Riemannian symmetric space. For any Zariski dense discrete subgroup $\Gamma<G$, we…

Spectral Theory · Mathematics 2023-11-08 Sam Edwards , Mikolaj Fraczyk , Minju Lee , Hee Oh

Fefferman and Graham showed some time ago that four dimensional conformal geometries could be analyzed in terms of six dimensional, ambient, Riemannian geometries admitting a closed homothety. Recently it was shown how conformal geometry…

High Energy Physics - Theory · Physics 2014-11-21 Roberto Bonezzi , Emanuele Latini , Andrew Waldron

Although the cosmological perturbations with inverse-volume corrections from loop quantum cosmology have been studied using the anomaly-free algebra approach in much of the literature, there still remains an important issue that some…

General Relativity and Quantum Cosmology · Physics 2018-10-18 Yu Han

Area metrics and area metric backgrounds provide a unified framework for quantum gravity. They encode physical degrees of freedom beyond those of a metric. These non-metric degrees of freedom must be suppressed by a potential at…

High Energy Physics - Theory · Physics 2024-08-20 Johanna Borissova , Pei-Ming Ho

We study the eigenvalues of the magnetic Schroedinger operator associated with a magnetic potential A and a scalar potential q, on a compact Riemannian manifold M, with Neumann boundary conditions if the boundary is not empty. We obtain…

Differential Geometry · Mathematics 2017-09-28 Bruno Colbois , Ahmad El Soufi , Said Ilias , Alessandro Savo

Consider a Hamiltonian action of a compact connected Lie group $G$ on an aspherical symplectic manifold $(M,\omega)$. Under some assumptions on $(M,\omega)$ and the action, D. A. Salamon conjectured that counting gauge equivalence classes…

Symplectic Geometry · Mathematics 2012-09-28 Fabian Ziltener

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

We summarize the basics of the loop representation of quantum gravity and describe the main aspects of the formalism, including its latest developments, in a reorganized and consistent form. Recoupling theory, in its graphical…

General Relativity and Quantum Cosmology · Physics 2011-09-09 Roberto De Pietri , C. Rovelli

By virtue of the Noether theorems, the vast gauge redundancy of general relativity provides us with a rich algebra of boundary charges that generate physical symmetries. These charges are located at codimension-2 entangling surfaces called…

High Energy Physics - Theory · Physics 2024-03-26 Laurent Freidel , Marc Geiller , Wolfgang Wieland

Physical properties of the quantum gravitational vacuum state are explored by solving a lattice version of the Wheeler-DeWitt equation. The constraint of diffeomorphism invariance is strong enough to uniquely determine the structure of the…

High Energy Physics - Theory · Physics 2015-06-12 Herbert W. Hamber , Reiko Toriumi , Ruth M. Williams

We present a gauge-invariant treatment of singularity resolution using loop quantum gravity techniques with respect to local SU(2) transformations. Our analysis reveals many novel features of quantum geometry which were till now hidden in…

General Relativity and Quantum Cosmology · Physics 2020-03-31 Klaus Liegener , Parampreet Singh

In Loop Quantum Gravity, tremendous progress has been made using the Ashtekar-Barbero variables. These variables, defined in a gauge-fixing of the theory, correspond to a parametrization of the solutions of the so-called simplicity…

General Relativity and Quantum Cosmology · Physics 2018-05-09 Christoph Charles

The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Carlo Rovelli

Starting from a Hamiltonian description of four dimensional general relativity in presence of a cosmological constant we perform the program of canonical quantisation. This is done using complex Ashtekar variables while keeping the…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Wolfgang Wieland