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Related papers: Loop quantum cosmology: From pre-inflationary dyna…

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Understanding the behavior of the universe at large depends critically on insights about the smallest units of matter and their fundamental interactions. Inflationary cosmology is a highly successful framework for exploring these…

Astrophysics · Physics 2009-11-10 Alan H. Guth , David I. Kaiser

A Planck scale inflationary era -- in a quantum gravity theory predicting discreteness of quantum geometry at the fundamental scale -- produces the scale invariant spectrum of inhomogeneities with very small tensor-to-scalar ratio of…

General Relativity and Quantum Cosmology · Physics 2025-04-30 Gabriel R. Bengochea , Gabriel Leon , Alejandro Perez

The primordial spectrum of cosmological tensor perturbations is considered as a possible probe of quantum gravity effects. Together with string theory, loop quantum gravity is one of the most promising frameworks to study quantum effects in…

General Relativity and Quantum Cosmology · Physics 2009-04-09 J. Grain , A. Barrau

The theory of cosmological fluctuations assumes that the pre-inflationary state of the universe was the quantum vacuum of a scalar field(s) coupled to gravity. The observed cosmic microwave background fluctuations are then interpreted as…

High Energy Physics - Theory · Physics 2016-05-03 S. P. de Alwis

Loop quantum cosmology provides a nice solution of avoiding the big bang singularity through a big bounce mechanism in the high energy region. In loop quantum cosmology an inflationary universe is emergent after the big bounce, no matter…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Xin Zhang , Yi Ling

Informed by a quantum information perspective, we interpret cosmological expansion of space as growing entanglement between underlying degrees of freedom. In particular, we focus on inflationary cosmology, which, while being a successful…

General Physics · Physics 2021-09-10 Ashmeet Singh , Olivier Doré

Cosmological perturbations are generally described by quantum fields on (curved but) classical space-times. While this strategy has a large domain of validity, it can not be justified in the quantum gravity era where curvature and matter…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Ivan Agullo , Abhay Ashtekar , William Nelson

Quantum effects play an essential role in modern cosmology. Perhaps the most striking example comes from large-scale structures, generally assumed to originate from vacuum quantum fluctuations and stretched by an expansion phase. Inflation…

General Relativity and Quantum Cosmology · Physics 2020-10-08 Emmanuel Frion

A major challenge at the interface of quantum gravity and cosmology is to explain the emergence of the large-scale structure of the Universe from Planck scale physics. In this letter, we extract the dynamics of scalar isotropic cosmological…

General Relativity and Quantum Cosmology · Physics 2024-08-23 Alexander F. Jercher , Luca Marchetti , Andreas G. A. Pithis

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

We investigate the observational signatures of quantum cosmology in the Cosmic Microwave Background data provided by Planck collaboration. We apply the warm inflationary paradigm with a tachyon scalar field to the loop quantum cosmology. In…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Vahid Kamali , Spyros Basilakos , Ahmad Mehrabi , Meysam Motaharfar , Erfan Massaeli

In loop quantum gravity, modifications to the geometrical density cause a self-interacting scalar field to accelerate away from a minimum of its potential. In principle, this mechanism can generate the conditions that subsequently lead to…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Martin Bojowald , James E. Lidsey , David J. Mulryne , Parampreet Singh , Reza Tavakol

The status of quantum cosmologies as testable models of the early universe is assessed in the context of inflation. While traditional Wheeler-DeWitt quantization is unable to produce sizable effects in the cosmic microwave background, the…

General Relativity and Quantum Cosmology · Physics 2013-10-08 Gianluca Calcagni

This Chapter provides an up to date, pedagogical review of some of the most relevant advances in loop quantum cosmology. We review the quantization of homogeneous cosmological models, their singularity resolution and the formulation of…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Ivan Agullo , Alejandro Corichi

We discuss the way non-perturbative quantization of cosmological spacetimes in loop quantum cosmology provides insights on the physics of Planck scale and the resolution of big bang singularity. In recent years, rigorous examination of…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Parampreet Singh

Loop quantum cosmology of the closed isotropic model is studied with a special emphasis on a comparison with traditional results obtained in the Wheeler-DeWitt approach. This includes the relation of the dynamical initial conditions with…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Martin Bojowald , Kevin Vandersloot

Quantum gravity has long been thought to be completely decoupled from experiments or observations. Although it is true that smoking guns are still missing, there are now serious hopes that quantum gravity phenomena might be tested. We…

General Relativity and Quantum Cosmology · Physics 2015-10-29 A. Barrau , J. Grain

We derive the primordial power spectra and spectral indexes of the density fluctuations and gravitational waves in the framework of loop quantum cosmology (LQC) with holonomy and inverse-volume corrections, by using the uniform asymptotic…

General Relativity and Quantum Cosmology · Physics 2015-08-04 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng , Qiang Wu

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…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Klaus Liegener , Parampreet Singh

This work is an analytical study of the main differences between classical inflationary effects of a fast-roll regime and imprints of hybrid Loop Quantum Cosmology (LQC) on the primordial power spectrum. Effective LQC solutions of…

General Relativity and Quantum Cosmology · Physics 2021-10-01 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán