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Related papers: Loop quantum cosmology of Bianchi type IX models

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This work applies the formalism developed in our earlier paper to de Sitter space. After exactly solving the relevant Heisenberg equations of motion we give a detailed discussion of the subtleties associated with defining physical states…

High Energy Physics - Theory · Physics 2007-05-23 Marvin Weinstein , Ratin Akhoury

The present work shows that a properly chosen ordering of operators can restore unitarity in anisotropic quantum cosmological models. Bianch V and Bianchi IX models with a perfect fluid are worked out. It has been shown that a…

General Relativity and Quantum Cosmology · Physics 2015-02-27 Sridip Pal , Narayan Banerjee

We have recently introduced an approach for studying perturbatively classical and quantum canonical general relativity. The perturbative technique appears to preserve many of the attractive features of the non-perturbative quantization…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Rodolfo Gambini , Jorge Pullin

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

We re-examine the issue of singularity resolution in homogeneous loop quantum cosmology from the perspective of geometrical entities such as expansion rate and the shear scalar. These quantities are very reliable measures of the properties…

General Relativity and Quantum Cosmology · Physics 2009-09-01 Alejandro Corichi , Parampreet Singh

We investigate the $\phi^2$ inflationary model in the Bianchi-I spacetime using effective spacetime description of loop quantum cosmology to understand the issues of the resolution of initial singularity, isotropization, effect of…

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

We have examined the cosmological actions of LRS (Locally Rationally Symmetric) Bianchi type-I universe model in $f(R,T^\psi)$ gravity. For this, we have estimated the Hubble parameter, the effective equation of state parameter…

General Relativity and Quantum Cosmology · Physics 2026-01-07 Mohit Thakre , Praveen Kumar Dhankar , Safiqul Islam , Parbati Sahoo , Farook Rahaman , Behnam Pourhassan

A new routine is proposed to relate Loop Quant Cosmology (LQC) to Loop Quantum Gravity (LQG) from the perspective of effective dynamics. We derive the big-bang singularity resolution and big bounce from the first principle of full canonical…

General Relativity and Quantum Cosmology · Physics 2020-02-12 Muxin Han , Hongguang Liu

We construct and study Loop Quantum Cosmology (LQC) when the Barbero-Immirzi parameter takes the complex value $\gamma=\pm i$. We refer to this new quantum cosmology as complex Loop Quantum Cosmology. We proceed in making an analytic…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Jibril Ben Achour , Julien Grain , Karim Noui

Spatially homogeneous cosmological models reduce to Hamiltonian systems in a low dimensional Minkowskian space moving on the total energy shell $H=0$. Close to the initial singularity some models (those of Bianchi type VIII and IX) can be…

General Relativity and Quantum Cosmology · Physics 2015-06-25 R. Graham

In order to deal with a large cosmological constant a relaxation mechanism based on modified gravity has been proposed recently. By virtue of this mechanism the effect of the vacuum energy density of a given quantum field/string theory (no…

General Relativity and Quantum Cosmology · Physics 2012-01-31 Spyros Basilakos , Florian Bauer , Joan Sola

The occurrence of singularities where spacetime curvature becomes infinite and geodesic evolution breaks down are inevitable events in classical general relativity (GR) unless one chooses an exotic matter violating weak energy condition.…

General Relativity and Quantum Cosmology · Physics 2024-11-05 Bao-Fei Li , Parampreet Singh

Loop quantum gravity in its Hamiltonian form relies on a connection formulation of the gravitational phase space with three key properties: 1.) a compact gauge group, 2.) real variables, and 3.) canonical Poisson brackets. In conjunction,…

General Relativity and Quantum Cosmology · Physics 2024-12-09 Norbert Bodendorfer , Konstantin Eder , Xiangdong Zhang

We discuss the quantization of vacuum Bianchi I spacetimes in the modified formalism of loop quantum cosmology recently proposed by Dapor and Liegener. This modification is based on a regularization procedure where both the Euclidean and…

General Relativity and Quantum Cosmology · Physics 2020-01-29 Alejandro Garcia-Quismondo , Guillermo A. Mena Marugan

Loop quantum gravity and cosmology are reviewed with an emphasis on evaluating the dynamics, rather than constructing it. The three crucial parts of such an analysis are (i) deriving effective equations, (ii) controlling the theory's…

General Relativity and Quantum Cosmology · Physics 2011-01-31 Martin Bojowald

It has been suggested that the homogeneous black hole interior spacetime, when quantized following the techniques of loop quantum cosmology, has a resolved singularity replaced by a black-to-white hole transition. This result has however…

General Relativity and Quantum Cosmology · Physics 2021-03-23 Francesco Sartini , Marc Geiller

Loop Quantum Cosmology strongly modifies the high-energy dynamics of Friedman-Robertson-Walker models and removes the big-bang singularity. We investigate how LQC corrections affect the stability properties of the Einstein static universe.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Luca Parisi , Marco Bruni , Roy Maartens , Kevin Vandersloot

We present a quantum version of the vacuum Bianchi IX model by implementing affine coherent state quantization combined with a Born-Oppenheimer-like adiabatic approximation. The analytical treatment is carried out on both quantum and…

General Relativity and Quantum Cosmology · Physics 2015-09-16 Hervé Bergeron , Ewa Czuchry , Jean Pierre Gazeau , Przemysław Małkiewicz , Włodzimierz Piechocki

Loop quantum cosmology allows for arbitrary superpositions of the triad variable. We show here how these superpositions can become indistinguishable from a classical mixture by the interaction with fermions. We calculate the reduced density…

General Relativity and Quantum Cosmology · Physics 2013-01-23 Claus Kiefer , Christian Schell

We present results concerning the nature of the cosmological big bounce(BB) transition within the loop geometry underlying loop quantum cosmology (LQC). Our canonical quantization method is an alternative to the standard LQC. An evolution…

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