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We numerically solve the effective loop quantum cosmology dynamics for the vacuum Bianchi type II and type IX spacetimes, in particular studying how the Kasner exponents evolve across the loop quantum cosmology bounce. We find that when the…

General Relativity and Quantum Cosmology · Physics 2023-10-11 Timothy Blackmore , Edward Wilson-Ewing

The effective quantum dynamics of Bianchi I spacetime is addressed within the statistical regularization scheme in Quantum Reduced Loop Gravity. The case of a minimally coupled massless scalar field is studied and compared with the…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Emanuele Alesci , Gioele Botta , Giovanni Luzi , Gabriele V. Stagno

We quantize the solution to the Belinski-Khalatnikov-Lifshitz (BKL) scenario using the integral quantization method. Quantization smears the gravitational singularity avoiding its localization in the configuration space. The latter is…

General Relativity and Quantum Cosmology · Physics 2023-03-01 Andrzej Góźdź , Aleksandra Pȩdrak , Włodzimierz Piechocki

We investigate Bianchi I cosmological model in the theory of a dilatonM field coupled to gravity through a Gauss-Bonnet term. Two type ofM cosmological singularity are distinguished. The former is analogous toM the Einstein gravity…

General Relativity and Quantum Cosmology · Physics 2009-10-31 S. Alexeyev , A. Toporensky , V. Ustiansky

The improved dynamics of loop quantum cosmology is extended to include the Bianchi type II model. Because these space-times admit both anisotropies and non-zero spatial curvature, certain technical difficulties arise over and above those…

General Relativity and Quantum Cosmology · Physics 2010-01-07 Abhay Ashtekar , Edward Wilson-Ewing

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

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

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

We numerically investigate the solutions to the effective equations of the Bianchi II model within the "improved" Loop Quantum Cosmology (LQC) dynamics. The matter source is a massless scalar field. We perform a systematic study of the…

General Relativity and Quantum Cosmology · Physics 2012-10-08 Alejandro Corichi , Edison Montoya

We analyze the quantum Bianchi I model in the setting of the nonstandard loop quantum cosmology. Elementary observables are used to quantize the volume operator. The spectrum of the volume operator is bounded from below and discrete. The…

General Relativity and Quantum Cosmology · Physics 2011-04-04 Przemyslaw Malkiewicz , Wlodzimierz Piechocki , Piotr Dzierzak

In this contribution we consider the issue of singularity resolution within loop quantum cosmology (LQC) for different homogeneous models. We present results of numerical evolutions of effective equations for both isotropic as well as…

General Relativity and Quantum Cosmology · Physics 2012-12-04 Alejandro Corichi , Asieh Karami , Edison Montoya

We analyze the semiclassical polymer dynamics of the inhomogeneous Mixmaster model by choosing the cubed scale factor as the discretized configurational variable, while the anisotropies remain pure Einsteinian variables. Such a modified…

General Relativity and Quantum Cosmology · Physics 2019-02-06 Stefano Antonini , Giovanni Montani

The well-known Bielinski-Khalatnikov-Lifshitz (BKL) scenario for the universe near the cosmological singularity is supplemented with a few exact results following from the BKL asymptotic of the Einstein equations: (1) The cosmological…

General Relativity and Quantum Cosmology · Physics 2025-05-22 Piotr P. Goldstein

We complete the canonical quantization of the vacuum Bianchi I model within the improved dynamics scheme of loop quantum cosmology, characterizing the Hilbert structure of the physical states and providing a complete set of observables…

General Relativity and Quantum Cosmology · Physics 2015-05-30 M Martín-Benito , L J Garay , G A Mena Marugán , E. Wilson-Ewing

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

The detailed formulation for loop quantum cosmology (LQC) in the Bianchi I model with a scalar massless field has been constructed. In this paper, its effective dynamics is studied in two improved strategies for implementing the LQC…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Dah-Wei Chiou

Loop quantum cosmological methods are extended to homogeneous models in diagonalized form. It is shown that the diagonalization leads to a simplification of the volume operator such that its spectrum can be determined explicitly. This…

General Relativity and Quantum Cosmology · Physics 2011-05-05 Martin Bojowald

The generic cosmological solution is analyzed both for the non-asymptotic limit to the cosmological singularity and in the asymptotic limit analytically. The Bianchi I solution and the Bianchi IX solution, described as a sequence of Bianchi…

General Relativity and Quantum Cosmology · Physics 2017-11-21 Orchidea Maria Lecian

Due to non-perturbative quantum gravitational effects, the classical big bang singularity is replaced by a quantum big bounce of the mean scale factor in loop quantization of Bianchi-I spacetime. An important issue is to understand various…

General Relativity and Quantum Cosmology · Physics 2012-07-30 Brajesh Gupt , Parampreet Singh