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Related papers: Loop Quantum Cosmology in Bianchi Type I Models: A…

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Using the ADM formalism in the minisuperspace, we obtain the commutative and noncommutative exact classical solutions and exact wave function to the Wheeler-DeWitt equation with an arbitrary factor ordering, for the anisotropic Bianchi type…

General Relativity and Quantum Cosmology · Physics 2015-05-14 J. Socorro , Luis O. Pimentel , C. Ortiz , M. Aguero

In this paper, a new Hamiltonian constraint operator for loop quantum cosmology is constructed by using the Chern-Simons action. The quantum dynamics of the $k=0$ cosmological model with respect to a massless scalar field as an emergent…

General Relativity and Quantum Cosmology · Physics 2019-09-23 Jinsong Yang , Cong Zhang , Yongge Ma

We study the late-time evolution of an anisotropic Bianchi-I universe with radiation in the framework of asymptotically safe gravity. We first discuss the radiation-dominated universe for the perfect fluid with the equation of state…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Chiang-Mei Chen , Ting-Kui Fan , Rituparna Mandal , Nobuyoshi Ohta

We study the locally rotational symmetry Bianchi type-I dark energy model in the framework of $f(T)$ theory of gravity, where $T$ denotes the torsion scalar. A viable cosmological model is undertaken and the isotropization of this latter is…

General Relativity and Quantum Cosmology · Physics 2014-01-13 M. E. Rodrigues , I. G. Salako , M. J. S. Houndjo , J. Tossa

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

Some long standing issues concerning the quantum nature of the big bang are resolved in the context of homogeneous isotropic models with a scalar field. Specifically, the known results on the resolution of the big bang singularity in loop…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Abhay Ashtekar , Tomasz Pawlowski , Parampreet Singh

We show how Loop Quantum Cosmology can be derived as an effective semiclassical description of Loop Quantum Gravity. Using the tools of QRLG, a gauge fixed version of LQG, we take the coherent states of the fundamental microscopic theory…

General Relativity and Quantum Cosmology · Physics 2014-10-20 Emanuele Alesci , Francesco Cianfrani

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

We present the method of describing an evolution in quantum cosmology in the framework of the reduced phase space quantization of loop cosmology. We apply our method to the flat Friedman-Robertson-Walker model coupled to a massless scalar…

General Relativity and Quantum Cosmology · Physics 2012-03-06 Jakub Mielczarek , Wlodzimierz Piechocki

A perturbative expansion of Loop Quantum Cosmological transitions amplitudes of Bianchi I models is performed. Following the procedure outlined in [1,2] for isotropic models, it is shown that the resulting expansion can be written in the…

General Relativity and Quantum Cosmology · Physics 2010-11-12 Miguel Campiglia , Adam Henderson , William Nelson

In the loop quantum cosmology effective dynamics for the vacuum Bianchi type I and type IX space-times, a non-singular bounce replaces the classical singularity. The bounce can be approximated as an instantaneous transition between two…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Edward Wilson-Ewing

In this work, we study some physical aspects of unitary evolution of Bianchi-I model. In particular, we study the behavior of the volume and the scale factor as a function of time for the Bianchi-I universe with ultra-relativistic fluid…

General Relativity and Quantum Cosmology · Physics 2016-01-28 Sridip Pal

In loop quantum cosmology, ambiguities in the Hamiltonian constraint can result in models with varying phenomenological predictions. In the homogeneous isotropic models, these ambiguities were settled, and the improved dynamics was found to…

General Relativity and Quantum Cosmology · Physics 2023-11-16 Meysam Motaharfar , Parampreet Singh , Eklavya Thareja

An improved Hamiltonian constraint operator is introduced in loop quantum cosmology. Quantum dynamics of the spatially flat, isotropic model with a massless scalar field is then studied in detail using analytical and numerical methods. The…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Abhay Ashtekar , Tomasz Pawlowski , Parampreet Singh

Understanding the early evolution of the universe requires models that incorporate possible quantum and anisotropic effects in its dynamics. In this work, we analyze the dynamical evolution of locally rotationally symmetric anisotropic…

General Relativity and Quantum Cosmology · Physics 2025-10-13 G. Oliveira-Neto , Y. Soncco Apaza

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

We study the implementation of Polymer Quantum Mechanics (PQM) to a system decomposed into a quasi-classical background and a small quantum subsystem, according to the original Vilenkin proposal. We develop the whole formalism in the…

General Relativity and Quantum Cosmology · Physics 2023-09-15 Eleonora Giovannetti , Giovanni Montani

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

Homogeneous, nearly-isotropic Bianchi cosmological models are considered. Their time evolution is expressed as a complete set of non-interacting linear modes on top of a Friedmann-Robertson-Walker background model. This connects the…

General Relativity and Quantum Cosmology · Physics 2011-09-08 Andrew Pontzen , Anthony Challinor

Contrary to the general belief, there has recently been quite a few examples of unitary evolution of quantum cosmological models. The present work gives more examples, namely Bianchi type VI and type II. These examples are important as they…

General Relativity and Quantum Cosmology · Physics 2016-11-03 Sachin Pandey , Narayan Banerjee
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