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Related papers: Absence of Singularity in Loop Quantum Cosmology

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It is widely believed that classical gravity breaks down and quantum gravity is needed to deal with a singularity. We show that there is a class of spacetime curvature singularities which can be resolved with metric and matter field…

General Relativity and Quantum Cosmology · Physics 2021-05-26 Atsushi Naruko , Chul-Moon Yoo , Misao Sasaki

Quantum gravitational effects in loop quantum cosmology lead to a resolution of the initial singularity and have the potential to solve the horizon problem and generate a quasi scale-invariant spectrum of density fluctuations. We consider…

Astrophysics · Physics 2008-11-26 Joao Magueijo , Parampreet Singh

Using the improved quantization technique to the mini-superspace approximation of loop quantum gravity, we study the evolution of black holes supported by a cosmological constant. The addition of a cosmological constant allows for classical…

General Relativity and Quantum Cosmology · Physics 2009-11-06 J. Brannlund , S. Kloster , A. DeBenedictis

Based on the observation that the exterior space-times of Schwarzschild-type solutions allow two symmetric slicings, a static spherically symmetric one and a timelike homogeneous one, modifications of gravitational dynamics suggested by…

General Relativity and Quantum Cosmology · Physics 2020-08-11 Martin Bojowald

The behaviour of the flat anisotropic model of the Universe with a scalar field is explored within the framework of quantum cosmology. The principal moment of the account of an anisotropy is the presence either negative potential barrier or…

General Relativity and Quantum Cosmology · Physics 2015-06-25 V. N. Folomeev , V. Ts. Gurovich

Quantum physics at scales large compared to the Planck scale is described in the framework of classical space-time geometries. A criterion for selecting these backgrounds out of quantized gravity is proposed. It leads to an instability of…

General Relativity and Quantum Cosmology · Physics 2009-09-25 F. Englert

Two spatial regions $B$ and $R$ are hyperentangled if the generalized entropy satisfies $S_{\text{gen}}^{B\cup R}<S_{\text{gen}}^R$. If in addition all future (or all past) directed inward null shape deformations of $B$ decrease…

High Energy Physics - Theory · Physics 2023-03-30 Raphael Bousso , Arvin Shahbazi-Moghaddam

Quantum cosmology is usually studied quantizing symmetry-reduced variables. Is it possible, instead, to define quantum cosmology starting from the full quantum gravity theory? In Loop Quantum Gravity (LQG), it is possible to cut the degrees…

General Relativity and Quantum Cosmology · Physics 2011-10-18 Francesca Vidotto

The approach of a quantum state to a cosmological singularity is studied through the evolution of its moments in a simple version of a Bianchi I model. In spite of the simplicity, the model exhibits several instructive and unexpected…

General Relativity and Quantum Cosmology · Physics 2020-06-03 Ana Alonso-Serrano , Martin Bojowald , David Brizuela

In arXiv:2603.18175, the authors argue, based on numerical studies of particular cases, that the quantum damping of cosmological shear in a modified loop quantum cosmological model (mLQC-I) that was recently found in arXiv:2510.14021 is not…

General Relativity and Quantum Cosmology · Physics 2026-04-13 Wen-Cong Gan , Leila L. Graef , Rudnei O. Ramos , Gustavo S. Vicente , Anzhong Wang

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

The cosmological singularities of the Bianchi I universe are analyzed in the setting of loop geometry underlying the loop quantum cosmology. We solve the Hamiltonian constraint of the theory and find the Lie algebra of elementary…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Piotr Dzierzak , Wlodzimierz Piechocki

All existing experimental results are currently interpreted using classical geometry. However, there are theoretical reasons to suspect that at a deeper level, geometry emerges as an approximate macroscopic behavior of a quantum system at…

Quantum Physics · Physics 2012-08-21 Craig Hogan

Resolution of singularities in the Kantowski-Sachs model due to non-perturbative quantum gravity effects is investigated. Using the effective spacetime description for the improved dynamics version of loop quantum Kantowski-Sachs…

General Relativity and Quantum Cosmology · Physics 2017-04-14 Sahil Saini , Parampreet Singh

A fundamental issue for any quantum cosmological theory is to specify how probabilities can be assigned to various quantum events or sequences of events such as the occurrence of singularities or bounces. In previous work, we have…

General Relativity and Quantum Cosmology · Physics 2013-10-02 David A. Craig , Parampreet Singh

In the present work, we study the noncommutative version of a quantum cosmology model. The model has a Friedmann-Robertson-Walker geometry, the matter content is a radiative perfect fluid and the spatial sections have zero constant…

General Relativity and Quantum Cosmology · Physics 2016-05-05 G. Oliveira-Neto , M. Silva de Oliveira , G. A. Monerat , E. V. Corrêa Silva

The quantum theory of the spherically symmetric gravity in 3+1 dimensions is investigated. The functional measures are explicitly evaluated and the physical state conditions are derived by using the technique developed in two dimensional…

High Energy Physics - Theory · Physics 2007-05-23 Ken-ji Hamada , Asato Tsuchiya

We construct a formalism for evolving spherically symmetric black hole initial data sets within a canonical approach to quantum gravity. This problem can be formulated precisely in quantum reduced loop gravity, a framework which has been…

General Relativity and Quantum Cosmology · Physics 2019-09-13 Emanuele Alesci , Sina Bahrami , Daniele Pranzetti

In massless scalar field cosmology, imposing the universe's physical volume as fundamentally discrete resolves the big bang singularity via a big bounce. We use quantum field theory on curved background to numerically track the number of…

General Relativity and Quantum Cosmology · Physics 2025-10-16 Mustafa Saeed , Irfan Javed , Aiman Nauman

A number of physical systems exhibit a particular form of asymptotic conformal invariance: within a particular range of distances, they are characterized by a long-range conformal interaction (inverse square potential), the absence of…

High Energy Physics - Theory · Physics 2007-05-23 Horacio E. Camblong , Carlos R. Ordonez