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Related papers: Non-Gaussianity in Loop Quantum Cosmology

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Loop Quantum Gravity (L.Q.G.) is one of the two most promising tentative theory for a quantum description of gravity. When applied to the entire universe, the so-called Loop Quantum Cosmology (L.Q.C.) framework offers microscopical models…

General Relativity and Quantum Cosmology · Physics 2014-11-20 J. Grain

We obtain exact expressions for the effect of primordial non-Gaussianity on the matter density perturbation up to second order in a LambdaCDM cosmology, fully accounting for the general relativistic corrections arising on scales comparable…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 N. Bartolo , S. Matarrese , O. Pantano , A. Riotto

Research during the last decade demonstrates that effects originating on the Planck scale are currently being tested in multiple observational contexts. In this review we discuss quantum gravity phenomenological models and their possible…

General Relativity and Quantum Cosmology · Physics 2012-12-14 Florian Girelli , Franz Hinterleitner , Seth A. Major

We formulate the transition from decelerated to accelerated expansion as a bounce in connection space and study its quantum cosmology, knowing that reflections are notorious for bringing quantum effects to the fore. We use a formalism for…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Steffen Gielen , João Magueijo

Since a positive future detection of non-linearity in the cosmic microwave background anisotropy pattern might allow to descriminate among different mechanisms giving rise to cosmological adiabatic perturbations, we study the evolution of…

High Energy Physics - Phenomenology · Physics 2010-02-10 N. Bartolo , S. Matarrese , A. Riotto

Cosmological models where the standard big bang is replaced by a bounce have been studied for decades. The situation has, however, dramatically changed in the past years for two reasons: first, because new ways to probe the early Universe…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-17 J. Grain , A. Barrau , T. Cailleteau , J. Mielczarek

Loop quantum cosmology(LQC) is the symmetric model of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogenous cosmological…

General Relativity and Quantum Cosmology · Physics 2016-10-13 Xiangdong Zhang

We explore the relationship between the effective dynamics in standard loop quantum cosmology (LQC) based on holonomies and triads obtained from gauge-fixing fluxes, and a modification of LQC based on holonomies and gauge-covariant fluxes…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Bao-Fei Li , Parampreet Singh

The very early universe provides the best arena we currently have to test quantum gravity theories. The success of the inflationary paradigm in accounting for the observed inhomogeneities in the cosmic microwave background already…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Abhay Ashtekar

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

The primordial Universe can be used as a laboratory to set constraints on quantum gravity. In the framework of Loop Quantum Cosmology, we show that such a proposal for quantum gravity not only solves for the big bang singularity issue but…

General Relativity and Quantum Cosmology · Physics 2012-06-08 Julien Grain

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

Non-perturbative quantum geometric effects in Loop Quantum Cosmology predict a $\rho^2$ modification to the Friedmann equation at high energies. The quadratic term is negative definite and can lead to generic bounces when the matter energy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Parampreet Singh , Kevin Vandersloot , G. V. Vereshchagin

In loop quantum cosmology (LQC) the big bang is replaced by a quantum bounce which is followed by a robust phase of super-inflation. Rather than growing unboundedly in the past, the Hubble parameter \emph{vanishes} at the bounce and attains…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Abhay Ashtekar , David Sloan

Loop Quantum Cosmology (LQC) is a theory which renders the Big Bang initial singularity into a quantum bounce, by means of short range repulsive quantum effects at the Planck scale. In this work, we are interested in reproducing the…

General Relativity and Quantum Cosmology · Physics 2021-11-25 Marcello Miranda , Daniele Vernieri , Salvatore Capozziello , Francisco S. N. Lobo

Over the last few years, it was realised that non-canonical scalar fields can lead to the accelerated expansion in the early universe. The primordial spectrum in these scenarios not only shows near scale-invariance consistent with CMB…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-05 Corrado Appignani , Roberto Casadio , S. Shankaranarayanan

Cosmological perturbation theory is a key tool to study the universe. The linear or first order theory is well understood, however, developing and applying the theory beyond linear order is at the cutting edge of current research in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Adam J. Christopherson

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…

General Relativity and Quantum Cosmology · Physics 2024-10-22 Rita B. Neves

Loop Quantum Cosmology (LQC), mainly due to Bojowald, is not the cosmological sector of Loop Quantum Gravity (LQG). Rather, LQC consists of a truncation of the phase space of classical General Relativity to spatially homogeneous situations…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Johannes Brunnemann , Thomas Thiemann

In this Essay we investigate the observational signatures of Loop Quantum Cosmology (LQC) in the CMB data. First, we concentrate on the dynamics of LQC and we provide the basic cosmological functions. We then obtain the power spectrum of…

General Relativity and Quantum Cosmology · Physics 2017-11-22 Spyros Basilakos , Vahid Kamali , Ahmad Mehrabi