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Related papers: Loop quantum cosmology of Bianchi IX: Effective dy…

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In loop quantum cosmology, non-perturbative quantum gravity effects lead to the resolution of the big bang singularity by a quantum bounce without introducing any new degrees of freedom. Though fundamentally discrete, the theory admits a…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Gonzalo J. Olmo , Parampreet Singh

We study anisotropic Bianchi-I cosmology, incorporating quantum gravitational corrections into the Einstein equation through the scale-dependent Newton coupling and cosmological term, as determined by the flow equation of the effective…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Chiang-Mei Chen , Akihiro Ishibashi , Rituparna Mandal , Nobuyoshi Ohta

In this article, we study the equations driving the dynamics of a Bianchi-I universe described by holonomy corrected effective loop quantum cosmology. We derive the LQC-modified generalized Friedmann equation, which is used as a guide to…

General Relativity and Quantum Cosmology · Physics 2014-07-28 Linda Linsefors , Aurelien Barrau

We study the anisotropic Bianchi I loop quantum cosmology in 2+1 dimensions. Both the $\mubar$ and $\mubar'$ schemes are considered in the present paper and the following expected results are established: (i) the massless scalar field again…

General Relativity and Quantum Cosmology · Physics 2020-10-23 You Ding , Xiangdong Zhang

We examine the dynamical consequences of homogeneous cosmological magnetic fields in the framework of loop quantum cosmology. We show that a big-bounce occurs in a collapsing magnetized Bianchi I universe, thus extending the known cases of…

General Relativity and Quantum Cosmology · Physics 2008-12-11 Roy Maartens , Kevin Vandersloot

We analyze the loop quantization of the family of vacuum Bianchi I spacetimes, a gravitational system whose classical solutions describe homogeneous anisotropic cosmologies. We rigorously construct the operator that represents the…

General Relativity and Quantum Cosmology · Physics 2009-02-20 M. Martin-Benito , G. A. Mena Marugan , T. Pawlowski

Isotropic models in loop quantum cosmology allow explicit calculations, thanks largely to a completely known volume spectrum, which is exploited in order to write down the evolution equation in a discrete internal time. Because of genuinely…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Martin Bojowald

In this paper we introduce a numerical approximation technique to obtain pre-classical solutions to models of loop quantum gravity. In particular, we apply the technique to vacuum Bianchi I cosmological models and recover known solutions.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Seth Connors , Gaurav Khanna

In this work we construct an effective four-dimensional model by compactifying a ten-dimensional theory of gravity coupled with a real scalar dilaton field on a time-dependent torus. The corresponding action in four dimensions is similar to…

General Relativity and Quantum Cosmology · Physics 2018-04-03 J. Socorro , L. Toledo Sesma , Luis O. Pimentel

This paper investigates Bianchi I spacetimes within the Jordan frame of Brans-Dicke theory, incorporating the framework of effective loop quantum gravity. After developing general formulas, we analyze the robustness of classical singularity…

General Relativity and Quantum Cosmology · Physics 2025-02-21 Manabendra Sharma , Gustavo S. Vicente , Leila L. Graef , Rudnei O. Ramos , Anzhong Wang

We present a novel cosmological model in which scalar field matter in a biaxial Bianchi IX geometry leads to a non-singular `pancaking' solution: the hypersurface volume goes to zero instantaneously at the `Big Bang', but all physical…

General Relativity and Quantum Cosmology · Physics 2009-03-12 Pierre-Philippe Dechant , Anthony N. Lasenby , Michael P. Hobson

The physical interpretation and eventual fate of gravitational singularities in a theory surpassing classical general relativity are puzzling questions that have generated a great deal of interest among various quantum gravity approaches.…

General Relativity and Quantum Cosmology · Physics 2019-11-06 Norbert Bodendorfer , Fabio M. Mele , Johannes Münch

We study the dynamics of the vacuum Bianchi IX model with timelike singularity and compare it with the dynamics of the Bianchi IX model with cosmological singularity. We show that differences in the signs of some terms in the set of…

General Relativity and Quantum Cosmology · Physics 2017-06-27 S. L. Parnovsky , W. Piechocki

A characteristic feature of loop quantization of the isotropic and Bianchi-I spacetimes is the existence of universal bounds on the energy density and the expansion and shear scalars, independent of the matter content. We investigate the…

General Relativity and Quantum Cosmology · Physics 2012-02-09 Brajesh Gupt , Parampreet Singh

We propose a quantum symmetry reduction of loop quantum gravity to Bianchi I spacetimes. To this end, we choose the diagonal metric gauge for the spatial diffeomorphism constraint at the classical level, leading to an…

General Relativity and Quantum Cosmology · Physics 2015-04-16 Norbert Bodendorfer

We consider the Bianchi I geometry coupled to several species of comoving barotropic perfect fluids with a linear equation of state in the context of general relativity. The solution of the dynamics can be reduced to a quadrature, which can…

General Relativity and Quantum Cosmology · Physics 2024-10-29 David Brizuela , Sara F. Uria

We perform an analysis of the Einstein-Skyrme cosmological model in Bianchi-IX background. We analytically describe asymptotic regimes and semi-analytically -- generic regimes. It appears that depending on the product of Newtonian constant…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Sergey A. Pavluchenko

We provide a quantum picture for the emergence of a bouncing cosmology, according to the idea that a semiclassical behavior of the Universe towards the singularity is not available in many relevant Minisuperspace models. In particular, we…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Eleonora Giovannetti , Giovanni Montani

The purpose of this work is to investigate spatially homogeneous and flat cosmological solutions of the Einstein equations coupled to a non-variational ``near-minimal'' scalar field. This coupling model represents a minimal departure from…

General Relativity and Quantum Cosmology · Physics 2026-05-05 Joshua Ritchie

The five-dimensional loop quantum Kaluza-Klein cosmology is constructed based on the symmetric reduction of the connection formulation of the full theory. Through semiclassical analysis, the effective scalar constraint for the cosmological…

General Relativity and Quantum Cosmology · Physics 2026-02-20 Shengzhi Li , Yongge Ma , Faqiang Yuan , Xiangdong Zhang