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We analyse the canonical quantum dynamics of the isotropic universe, as emerging from the Hamiltonian formulation of a metric f(R) gravity, viewed in the Jordan frame. The canonical method of quantization is performed by solving the…

General Relativity and Quantum Cosmology · Physics 2021-09-06 Mariaveronica De Angelis , Laria Figurato , Giovanni Montani

We present a noncommutative extension of Quantum Cosmology and study the Kantowski-Sachs (KS) cosmological model requiring that the two scale factors of the KS metric, the coordinates of the system, and their conjugate canonical momenta do…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Catarina Bastos , Orfeu Bertolami , Nuno Costa Dias , João Nuno Prata

Three of the big puzzles of theoretical physics are the following: (i) There is apparently no time evolution in the dynamics of quantum general relativity, because the allowed quantum states must obey the Hamiltonian constraint. (ii) During…

General Relativity and Quantum Cosmology · Physics 2015-12-29 Shreya Banerjee , Sayantani Bera , Tejinder P. Singh

We present a systematic study of the cosmological dynamics resulting from an effective Hamiltonian, recently derived in loop quantum gravity using Thiemann's regularization and earlier obtained in loop quantum cosmology (LQC) by keeping the…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Bao-Fei Li , Parampreet Singh , Anzhong Wang

In quantum cosmology, one applies quantum physics to the whole universe. While no unique version and no completely well-defined theory is available yet, the framework gives rise to interesting conceptual, mathematical and physical…

General Relativity and Quantum Cosmology · Physics 2015-01-21 Martin Bojowald

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 positive constant…

General Relativity and Quantum Cosmology · Physics 2016-05-05 G. Oliveira-Neto , G. A. Monerat , E. V. Corrêa Silva , C. Neves , L. G. Ferreira Filho

In this review, we focus on whether a canonical quantization of general relativity can produce testable predictions for cosmology. In particular, we examine how this approach can be used to model the evolution of primordial perturbations.…

General Relativity and Quantum Cosmology · Physics 2023-10-20 Leonardo Chataignier , Claus Kiefer , Paulo Moniz

We provide a cosmological implementation of the evolutionary quantum gravity, describing an isotropic Universe, in the presence of a negative cosmological constant and a massive (preinflationary) scalar field. We demonstrate that the…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Francesco Cianfrani , Giovanni Montani , Fabrizio Pittorino

Spherically symmetric, null dust clouds, like their time-like counterparts, may collapse classically into black holes or naked singularities depending on their initial conditions. We consider the Hamiltonian dynamics of the collapse of an…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Cenalo Vaz , Louis Witten , T. P. Singh

Recently, a model of modified gravity plus single scalar field model was proposed, in which the scalar couples both to the standard Riemannian volume form given by the square root of the determinant of the Riemannian metric, as well as to…

General Relativity and Quantum Cosmology · Physics 2016-12-09 Denitsa Staicova , Michail Stoilov

In the background of homogeneous and isotropic flat FLRW space-time, both classical and quantum cosmology has been studied for teleparallel dark energy (DE) model. Using Noether symmetry analysis, not only the symmetry vector but also the…

General Relativity and Quantum Cosmology · Physics 2024-07-12 Dipankar Laya , Roshni Bhaumik , Sourav Dutta , Subenoy Chakraborty

We investigate quantum cosmological models in an n-dimensional anisotropic universe in the presence of a massless scalar field. Our basic inspiration comes from Chodos and Detweiler's classical model which predicts an interesting behaviour…

General Relativity and Quantum Cosmology · Physics 2018-02-14 F. A. P. Alves-Júnior , M. L. Pucheu , A. B. Barreto , C. Romero

Quantum mechanics in its presently known formulation requires an external classical time for its description. A classical spacetime manifold and a classical spacetime metric are produced by classical matter fields. In the absence of such…

General Relativity and Quantum Cosmology · Physics 2008-11-26 T. P. Singh

We consider flat Friedmann-Lema\^{\i}tre-Robertson-Walker cosmological models in the framework of general scalar-tensor theories of gravity with arbitrary coupling functions, set in the Jordan frame, in the cosmological epoch when the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Laur Järv , Piret Kuusk , Margus Saal

The loop quantum gravitational collapse of the dust ball in presence of positive cosmological constant is investigated within the Oppenheimer-Snyder collapse scenario. The dust ball interior is described within the framework of loop quantum…

General Relativity and Quantum Cosmology · Physics 2025-07-31 Michał Bobula , Tomasz Pawłowski

A discussion is given of the quantisation of a physical system with finite degrees of freedom subject to a Hamiltonian constraint by treating time as a constrained classical variable interacting with an unconstrained quantum state. This…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Charles Wang

Quantum geometrodynamics (QGD) in extended phase space essentially distinguished from the Wheeler - DeWitt QGD is proposed. The grounds for constructing a new version of quantum geometrodynamics are briefly discussed. The main part in the…

General Relativity and Quantum Cosmology · Physics 2011-04-15 T. P. Shestakova

The Wheeler-DeWitt equation for a class of Kantowski-Sachs like models is completely solved. The generalized models include the Kantowski-Sachs model with cosmological constant and pressureless dust. Likewise contained is a joined model…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Heinz-Dieter Conradi

The thermodynamic properties of loop quantum cosmology (LQC) without considering the Lorentz term were established in \cite{Zhu09}. In this paper, we extend this result to the recent proposed new model of LQC with the Lorentz term. We…

General Relativity and Quantum Cosmology · Physics 2021-11-11 Xiangdong Zhang

This work concerns a new reformulation of quantum geometrodynamics, which allows to overcome a fundamental ambiguity contained in the canonical approach to quantum gravity: the possibility of performing a (3+1)-slicing of space-time, when…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Simone Mercuri , Giovanni Montani
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