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An alternative inflationary model is proposed predicated upon a consideration of the form of the uncertainty principle in a curved background spacetime. An argument is presented suggesting a possible curvature dependence in the correct…

General Relativity and Quantum Cosmology · Physics 2014-05-12 Paul J. Camp , John L. Safko

The FRW model with non-minimally coupled massive scalar field has been investigated in LQC framework. Considered form of the potential and coupling allows applications to Higgs driven inflation. Out of two frames used in the literature to…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Michal Artymowski , Andrea Dapor , Tomasz Pawlowski

The creation of ultra-light dark particles in the late-time FLRW spacetime provides a cosmological model in accordance with precise observational tests. The matter creation backreaction implies in this context a vacuum energy density…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-11 Saulo Carneiro

In this paper, we investigate the dynamics of pre-inflation with Hilltop potential in the framework of loop quantum cosmology. The initial conditions of inflaton field at the quantum bounce is categorized into two classes, first one is…

General Relativity and Quantum Cosmology · Physics 2023-02-03 M. Shahalam , Kuralay Yesmakhanova , Zhanar Umurzakhova

We provide an exhaustive numerical exploration of the predictions of loop quantum cosmology (LQC) with a post-bounce phase of inflation for the primordial power spectrum of scalar and tensor perturbations. We extend previous analysis by…

General Relativity and Quantum Cosmology · Physics 2015-12-30 Ivan Agullo , Noah A. Morris

In the framework of a flat FLRW model we derive an inflationary regime in which the scalar field, laying on the plateau of its potential, admits a linear time dependence and remains close to a constant value. The behaviour of inhomogeneous…

General Relativity and Quantum Cosmology · Physics 2016-11-09 Giovanni Imponente , Giovanni Montani

The usual description of inflationary fluctuations uses the framework of quantum field theory (QFT) in curved spacetime, in which quantum fluctuations are superimposed on a classical background spacetime. Even for large fluctuations, such…

General Relativity and Quantum Cosmology · Physics 2020-03-11 Sebastian F. Bramberger , Alice Di Tucci , Jean-Luc Lehners

During the inflationary epoch,geometry of the universe may be described by quasi-de Sitter space. On the other hand,maximally extended de Sitter metric in the comoving coordinates accords with a special FLRW model with positive spatial…

General Relativity and Quantum Cosmology · Physics 2016-01-20 A. A. Asgari , A. H. Abbassi

We consider an inflationary universe model in which the phase of accelerated expansion was preceded by a non-singular bounce and a period of contraction which involves a phase of deceleration. We follow fluctuations which exit the Hubble…

High Energy Physics - Theory · Physics 2009-03-15 Robert Brandenberger , Xinmin Zhang

A stiff matter-dominated universe modeled by a free massless scalar field minimally coupled to gravity in a Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) geometry is quantized. Generalized complex-width gaussian superpositions of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Felipe T. Falciano , Nelson Pinto-Neto , E. Sergio Santini

We make use of possible high energy correction to the Friedmann equation to implement the bounce and study the behavior of massive scalar field before and after bounce semianalytically and numerically. We find that the slow-roll inflation…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Yun-Song Piao , Yuan-Zhong Zhang

In this work, we investigate the (pre)-inflationary dynamics of a flat, homogeneous, and isotropic universe governed by the Starobinsky potential within the framework of noncommutative effective loop quantum cosmology. The field equations…

General Relativity and Quantum Cosmology · Physics 2025-12-05 Luis Rey Díaz-Barrón , Abraham Espinoza-García , Sinuhé Pérez-Payán , José Socorro

Until recently our knowledge of the primordial curvature perturbation was relatively modest. Ever since COBE delivered its map of data we know the scalar spectrum of primordial perturbations is approximately flat, with the power being only…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-24 Raquel H. Ribeiro

In loop quantum cosmology (LQC), the initial singularity is replaced by a quantum bounce, leading to a universal post-bounce evolution characterized by three distinct epochs: bouncing, transition, and slow-roll inflation, before the hot…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Yogesh , Bao-Fei Li , Mayukh R. Gangopadhyay , Anzhong Wang

We consider the description of cosmological dynamics from the onset of inflation by a perfect fluid whose parameters must be consistent with the strength of the enhanced quantum loop effects that can arise during inflation. The source of…

General Relativity and Quantum Cosmology · Physics 2010-04-14 N. C. Tsamis , R. P. Woodard

In this paper, we study inflation in the framework of the nonrelativistic general covariant theory of the Ho\v{r}ava-Lifshitz gravity with the projectability condition and an arbitrary coupling constant $\lambda$. We find that the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Yongqing Huang , Anzhong Wang , Qiang Wu

In some versions of the theory of inflation, it is assumed that before inflation began the universe was in a Friedmann-Robertson-Walker (FRW) stage, with the energy density dominated by massless particles. The origin of the nearly…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 Richard Lieu , T. W. B. Kibble

We study the evolution of quantum fluctuations of gravity around an inflationary solution in renormalizable quantum gravity, in which the initial scalar-fluctuation dominance is shown by the background-free nature expressed by a special…

High Energy Physics - Theory · Physics 2024-01-19 Ken-ji Hamada

We study the entire coupled evolution of the inflaton and the scale factor for general initial conditions at a given initial time. The generic early universe evolution has three stages: decelerated fast-roll followed by inflationary fast…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-30 C. Destri , H. J. de Vega , N. G. Sanchez

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