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Related papers: Numerical loop quantum cosmology: an overview

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Several examples are known where quantum gravity effects resolve the classical big bang singularity by a bounce. The most detailed analysis has probably occurred for loop quantum cosmology of isotropic models sourced by a free, massless…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Martin Bojowald

We summarize our investigations of the second-order perturbations in loop quantum cosmology (LQC). We shall discuss, primarily, two aspects. Firstly, whether the second-order contributions arising from the cosmic bounce, occurring at Planck…

General Relativity and Quantum Cosmology · Physics 2019-04-03 Vijayakumar Sreenath , Ivan Agullo , Boris Bolliet

Since there are quantization ambiguities in constructing the Hamiltonian constraint operator in isotropic loop quantum cosmology, it is crucial to check whether the key features of loop quantum cosmology, such as the quantum bounce and…

General Relativity and Quantum Cosmology · Physics 2009-04-28 Jinsong Yang , You Ding , Yongge Ma

A consistent combination of quantum geometry effects rules out a large class of models of loop quantum cosmology and their critical densities as they have been used in the recent literature. In particular, the critical density at which an…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Martin Bojowald

Multiple scale techniques are well-known in classical mechanics to give perturbation series free from resonant terms. When applied to the quantum anharmonic oscillator, these techniques lead to interesting features concerning the solution…

High Energy Physics - Theory · Physics 2009-11-07 Guy Auberson , Michel Capdequi Peyranere

The loop quantization of the negatively curved k=-1 RW model poses several technical challenges. We show that the issues can be overcome and a successful quantization is possible that extends the results of the k=0,+1 models in a natural…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Kevin Vandersloot

In the last decades, progress on the quantization of black holes using techniques developed in loop quantum cosmology has received increasing attention. Due to the quantum geometry effect, the resulting quantum corrected black hole is free…

General Relativity and Quantum Cosmology · Physics 2023-08-22 Xiangdong Zhang

We re-examine the process of loop quantization for flat isotropic models in cosmology. In particular, we contrast different inequivalent `loop quantizations' of these simple models through their respective successes and limitations and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alejandro Corichi , Parampreet Singh

Loop Quantum Gravity is a background independent, nonperturbative approach to the quantization of General Relativity. Its application to models of interest in cosmology and astrophysics, known as Loop Quantum Cosmology, has led to new and…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Guillermo A. Mena Marugan

The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Carlo Rovelli

We present a review on basic aspects of quantum cosmology in the presence of cut-off physics. We first analyze how the Wheeler-DeWitt equation in a pure metric approach describes the quantum Universe, showing how the singularity is not…

General Relativity and Quantum Cosmology · Physics 2021-09-20 Gabriele Barca , Eleonora Giovannetti , Giovanni Montani

We examine the nature of the cosmological big-bounce (BB) transition within the loop geometry underlying Loop Quantum Cosmology (LQC) at classical and quantum levels. Our canonical quantization method is an alternative to the standard LQC.…

General Relativity and Quantum Cosmology · Physics 2015-05-14 Wlodzimierz Piechocki

As a first step to generalize the structure of loop quantum cosmology to the theories with the spacetime dimension other than four, the isotropic model of loop quantum cosmology in 2+1 dimension is studied in this paper. We find that the…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Xiangdong Zhang

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

A free massless scalar field is coupled to homogeneous and isotropic loop quantum cosmology. The coupled model is investigated in the vicinity of the classical singularity, where discreteness is essential and where the quantum model is…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Martin Bojowald , Franz Hinterleitner

Semiclassical states in isotropic loop quantum cosmology are employed to show that the improved dynamics has the correct classical limit. The effective Hamiltonian for the quantum cosmological model with a massless scalar field is thus…

General Relativity and Quantum Cosmology · Physics 2009-02-27 You Ding , Yongge Ma , Jinsong Yang

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

Computer simulations are enabling researchers to investigate systems which are extremely difficult to handle analytically. In the particular case of General Relativity, numerical models have proved extremely valuable for investigations of…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Luis Lehner

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

Loop quantum cosmology provides an efficient framework to study the evolution of the Universe beyond the classical Big Bang paradigm. Because of holonomy corrections, the singularity is replaced by a "bounce". The dynamics of the background…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Jakub Mielczarek , Thomas Cailleteau , Julien Grain , Aurelien Barrau