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We develop a relativistic framework to investigate the evolution of cosmological structures from the initial density perturbations to the highly nonlinear regime. Our approach involves proposing a procedure to match ``best-fit", exact…

General Relativity and Quantum Cosmology · Physics 2024-04-29 Przemyslaw Malkiewicz , Jan J. Ostrowski , Ismael Delgado Gaspar

A brief review of various numerical techniques used in loop quantum cosmology and results is presented. These include the way extensive numerical simulations shed insights on the resolution of classical singularities, resulting in the key…

General Relativity and Quantum Cosmology · Physics 2013-07-11 Parampreet Singh

We discuss the semiclassical limit of Quantum Reduced Loop Gravity, a recently proposed model to address the quantum dynamics of the early Universe. We apply the techniques developed in full Loop Quantum Gravity to define the semiclassical…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Emanuele Alesci , Francesco Cianfrani

We demonstrate a spontaneous tendency of quantum wave packets to become quasi-classical, providing a classical limit for the Universe dynamics. However, this limit is not maintained in the future (after a critical value of the relational…

General Relativity and Quantum Cosmology · Physics 2023-04-12 Mariaveronica De Angelis , Giovanni Montani

The mathematical structure of higher-dimensional physical phase spaces of the nondiagonal Bianchi IX model is analyzed in the neighborhood of the cosmological singularity by using dynamical system methods. Critical points of the Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Ewa Czuchry , Wlodzimierz Piechocki

We study the homogeneous but anisotropic cosmological models of Bianchi in presence of a massive scalar field using the ADM Hamiltonian formalism. We begin to describe the main steps to find the ADM Hamiltonian of the General Relativity…

General Relativity and Quantum Cosmology · Physics 2014-04-15 Stephane Fay

In the present paper we generalize the original work of C.W. Misner \cite{M69q} about the quantum dynamics of the Bianchi type IX geometry near the cosmological singularity. We extend the analysis to the generic inhomogeneous universe by…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Giovanni Imponente , Giovanni Montani

The detailed formulation for loop quantum cosmology (LQC) in the Bianchi I model with a massless scalar field was recently constructed. In this paper, its effective dynamics with the LQC discreteness corrections is studied and the equations…

General Relativity and Quantum Cosmology · Physics 2007-09-12 Dah-Wei Chiou

We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. In this way, a physical clock with discrete…

Quantum Physics · Physics 2007-05-23 H. -T. Elze

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

We study the evolution of Bianchi-I space-times filled with a global unidirectional electromagnetic field $F_{mn}$ interacting with a massless scalar dilatonic field according to the law \Psi(\phi) F^{mn} F_{mn} where \Psi(\phi) > 0 is an…

General Relativity and Quantum Cosmology · Physics 2009-11-10 K. A. Bronnikov , E. N. Chudaeva , G. N. Shikin

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

The Gowdy cosmologies are vacuum solutions to the Einstein equations which possess two space-like Killing vectors and whose spatial sections are compact. We consider the simplest of these cosmological models: the case where the spatial…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Mercedes Martín-Benito , Guillermo A. Mena Marugán , Edward Wilson-Ewing

In this article we perform the Wheeler-DeWitt quantization for Bianchi type $I$ anisotropic cosmological model in the presence of a scalar field minimally coupled to the Einstein-Hilbert gravity theory. We also consider the cosmological…

General Relativity and Quantum Cosmology · Physics 2019-08-14 Saumya Ghosh , Sunandan Gangopadhyay , Prasanta K. Panigrahi

Process of formation of the universe with its further expansion in the first evolution stage is investigated in the framework of Friedmann-Robertson-Walker metrics on the basis of quantum model, where a new type of matter is introduced,…

General Relativity and Quantum Cosmology · Physics 2013-01-17 Sergei P. Maydanyuk

It is shown that the cosmological singularity in isotropic minisuperspaces is naturally removed by quantum geometry. Already at the kinematical level, this is indicated by the fact that the inverse scale factor is represented by a bounded…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald

Bianchi type V bulk viscous fluid cosmological models are investigated with dynamic cosmological term $\Lambda(t)$. Using a generation technique (Camci {\it et al.}, 2001), it is shown that the Einstein's field equations are solvable for…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anirudh Pradhan , Kanti Jotania , Anju Rai

We investigate the effects of the underlying quantum geometry in loop quantum cosmology on spacetime curvature invariants and the extendibility of geodesics in the Bianchi-I model for matter with a vanishing anisotropic stress. Using the…

General Relativity and Quantum Cosmology · Physics 2012-07-05 Parampreet Singh

The action of the quantum mechanical volume operator, introduced in connection with a symmetric representation of the three-body problem and recently recognized to play a fundamental role in discretized quantum gravity models, can be given…

Quantum Physics · Physics 2013-10-22 Vincenzo Aquilanti , Dimitri Marinelli , Annalisa Marzuoli

We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. - This is motivated by the ``timeless''…

General Relativity and Quantum Cosmology · Physics 2015-06-25 H. -T. Elze