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相关论文: On (Cosmological) Singularity Avoidance in Loop Qu…

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In the recent years the quantization methods of Loop Quantum Gravity have been successfully applied to the homogeneous and isotropic Friedmann-Robertson-Walker space-times. The resulting theory, called Loop Quantum Cosmology (LQC), resolves…

广义相对论与量子宇宙学 · 物理学 2010-11-23 Michal Artymowski , Zygmunt Lalak , Lukasz Szulc

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…

广义相对论与量子宇宙学 · 物理学 2014-10-20 Emanuele Alesci , Francesco Cianfrani

In this PhD thesis, we introduced a new strategy to investigate the kinematical and physical predictions of self dual Loop Quantum Gravity (LQG) and by-passed the old problem of implementing quantum mechanically the so called reality…

广义相对论与量子宇宙学 · 物理学 2015-11-24 Jibril Ben Achour

It is known that in loop quantum cosmology (LQC) the universe avoids the singularity by a bounce when the matter density approaches the critical density $\rho_c$ (the order of Planck density). After incorporating the inverse volume…

广义相对论与量子宇宙学 · 物理学 2011-03-14 Hua-Hui Xiong , Jian-Yang Zhu

This article presents an "in-a-nutshell" yet self-contained introductory review on loop quantum gravity (LQG) -- a background-independent, nonperturbative approach to a consistent quantum theory of gravity. Instead of rigorous and…

广义相对论与量子宇宙学 · 物理学 2014-12-30 Dah-Wei Chiou

Loop quantum cosmology is a symmetry reduced quantization of cosmological spacetimes based on loop quantum gravity. While it has been successful in resolution of various cosmological singularities and connecting Planck scale physics to…

广义相对论与量子宇宙学 · 物理学 2019-12-25 Klaus Liegener , Parampreet Singh

The standard model of cosmology assumes a homogeneous and isotropic universe that undergoes a period of exponential expansion very early on, named inflation. This stretches quantum fluctuations from the onset of inflation to cosmological…

广义相对论与量子宇宙学 · 物理学 2024-10-22 Rita B. Neves

We apply the full theory of Loop Quantum Gravity (LQG) to cosmology and present a top-down derivation of gauge-invariant cosmological perturbation theory from quantum gravity. The derivation employs the reduced phase space formulation of…

广义相对论与量子宇宙学 · 物理学 2021-01-20 Muxin Han , Haida Li , Hongguang Liu

Loop Quantum Gravity is a nonperturbative and background independent program for the quantization of General Relativity. Its underlying formalism has been applied successfully to the study of cosmological spacetimes, both to test the…

广义相对论与量子宇宙学 · 物理学 2021-09-13 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán

The inverse scale factor, which in classical cosmological models diverges at the singularity, is quantized in isotropic models of loop quantum cosmology by using techniques which have been developed in quantum geometry for a quantization of…

广义相对论与量子宇宙学 · 物理学 2009-11-07 Martin Bojowald

It is well known that a closed universe with a minimally coupled massive scalar field always collapses to a singularity unless the initial conditions are extremely fine tuned. We show that the corrections to the equations of motion for the…

广义相对论与量子宇宙学 · 物理学 2009-11-10 Parampreet Singh , Alexey Toporensky

Quantum General Relativity (QGR), sometimes called Loop Quantum Gravity, has matured over the past fifteen years to a mathematically rigorous candidate quantum field theory of the gravitational field. The features that distinguish it from…

广义相对论与量子宇宙学 · 物理学 2015-06-25 Thomas Thiemann

In this paper we take matter source with non-linear Equation of state (EoS) that has produced non-singular Emergent cosmology for spatially flat universe in General Relativity and minimally coupled scalar field with two different potentials…

广义相对论与量子宇宙学 · 物理学 2023-10-23 Rikpratik Sengupta , B. C. Paul , M. Kalam , P. Paul , A. Aich

We explore the extension of quantum cosmology outside the homogeneous approximation, using the formalism of loop quantum gravity. We introduce a model where some of the inhomogeneous degrees of freedom are present, providing a tool for…

广义相对论与量子宇宙学 · 物理学 2008-12-18 Carlo Rovelli , Francesca Vidotto

In this contribution we consider the issue of singularity resolution within loop quantum cosmology (LQC) for different homogeneous models. We present results of numerical evolutions of effective equations for both isotropic as well as…

广义相对论与量子宇宙学 · 物理学 2012-12-04 Alejandro Corichi , Asieh Karami , Edison Montoya

We extend the phenomenology of loop quantum cosmology (LQC) to second order in perturbations. Our motivation is twofold. On the one hand, since LQC predicts a cosmic bounce that takes place at the Planck scale, the second order…

广义相对论与量子宇宙学 · 物理学 2018-04-04 Ivan Agullo , Boris Bolliet , V. Sreenath

The goal of spin foam models is to provide a viable path integral formulation of quantum gravity. Because of background independence, their underlying framework has certain novel features that are not shared by path integral formulations of…

广义相对论与量子宇宙学 · 物理学 2011-01-25 Abhay Ashtekar , Miguel Campiglia , Adam Henderson

Loop quantum cosmology (LQC) predicts a nonsingular evolution of the universe through a bounce in the high energy region. But LQC has an ambiguity about the quantization scheme. Recently, the authors in [Phys. Rev. D 77, 124008 (2008)]…

广义相对论与量子宇宙学 · 物理学 2014-11-18 Li-Fang Li , Jian-Yang Zhu

Cosmological perturbations in Loop Quantum Cosmology (LQC) are usually studied incorporating either holonomy corrections, where the Ashtekar connection is replaced by a suitable sinus function in order to have a well-defined quantum…

广义相对论与量子宇宙学 · 物理学 2015-06-17 Jaime Haro

Based on spherically symmetric reduction of loop quantum gravity, quantization of the portion interior to the horizon of a Reissner-Nordstr\"{o}m black hole is studied. Classical phase space variables of all regions of such a black hole are…

广义相对论与量子宇宙学 · 物理学 2012-08-14 Mojtaba Taslimi Tehrani , Hoshang Heydari