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We study the inflationary era of the Universe in a modified cosmological scenario based on the gravity-thermodynamics conjecture with Barrow entropy instead of the usual Bekenstein-Hawking one. The former arises from the effort to account…

General Relativity and Quantum Cosmology · Physics 2025-03-25 Giuseppe Gaetano Luciano

The physical history of the Universe is completed by including the quantum planckian and trans-planckian phase before Inflation in the Standard Model of the Universe in agreement with observations. A new quantum precursor phase appears…

General Relativity and Quantum Cosmology · Physics 2019-12-23 Norma G. Sanchez

We consider a noncommutative (NC) inflationary model with a homogeneous scalar field minimally coupled to gravity. The particular NC inflationary setting produces entirely new consequences. We first analyze the free field case and…

General Relativity and Quantum Cosmology · Physics 2018-05-01 S. M. M. Rasouli , N. Saba , M. Farhoudi , J. Marto , P. Moniz

We consider inflationary scenarios for FRLW supersymetric models with a scalar field, whose Wheeler-DeWitt equation has analytic solutions. Following previous work of the authors, we analyse the setting of the scalar field as clock, leading…

General Relativity and Quantum Cosmology · Physics 2022-02-03 N. E. Martínez-Pérez , C. Ramírez , V. Vázquez-Báez

We study and estimate probabilistic predictions for the duration of the preinflationary and slow-roll phases after the bounce in loop quantum cosmology, determining how the presence of radiation in the prebounce phase affects these results.…

General Relativity and Quantum Cosmology · Physics 2020-11-25 L. N Barboza , L. L. Graef , Rudnei O. Ramos

We model the large scale late time universe as a Lambda-CDM cosmology driven by cosmological constant and perfect dust fluid. Our aim is to find new solutions in the matter and Lambda epoch consistent with inflationary initial conditions,…

High Energy Physics - Theory · Physics 2013-05-29 Toby Wiseman , Benjamin Withers

We propose a method to extract predictions from quantum cosmology for inflation that can be confronted with observations. Employing the tunneling boundary condition in quantum geometrodynamics, we derive a probability distribution for the…

General Relativity and Quantum Cosmology · Physics 2015-07-21 Gianluca Calcagni , Claus Kiefer , Christian F. Steinwachs

We study oscillatory universes within the context of Loop Quantum Cosmology. We make a comparative study of flat and positively curved universes sourced by scalar fields with either positive or negative potentials. We investigate how…

General Relativity and Quantum Cosmology · Physics 2009-11-10 D. J. Mulryne , N. J. Nunes , R. Tavakol , J. E. Lidsey

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…

Astrophysics · Physics 2009-11-10 F. J. Cao , H. J. de Vega , N. G. Sanchez

By incorporating quantum aspects of gravity, Loop Quantum Cosmology (LQC) provides a self-consistent extension of the inflationary scenario, allowing for modifications in the primordial inflationary power spectrum with respect to the…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-01 Micol Benetti , Leila Graef , Rudnei O. Ramos

We investigate the initiation of cosmic inflation, in full numerical relativity, from pre-inflationary scenarios with large tensor and vector fluctuations in the metric. These settings are characterized by having large values in the Weyl…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-04 Cristian Joana

Closed, singularity-free, inflationary cosmological models have recently been studied in the context of general relativity. Despite their appeal, these so called emergent models suffer from a number of limitations. These include the fact…

Astrophysics · Physics 2009-11-10 David J. Mulryne , Reza Tavakol , James E. Lidsey , George F. R. Ellis

The physics of the inflationary universe requires the study of the out of equilibrium evolution of quantum fields in curved spacetime. We present the evolution for both the geometry and the matter (described by the quantum inflaton field)…

Astrophysics · Physics 2007-05-23 D. Boyanovsky , D. Cormier , H. J. de Vega , R. Holman , S. P. Kumar

An extremely fast exponential expansion of the Universe is typical for the stable version of the inflationary model, based on the anomaly-induced action of gravity. The total amount of exponential $e$-folds could be very large, before the…

High Energy Physics - Theory · Physics 2021-08-05 Wagno Cesar e Silva , Ilya L. Shapiro

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…

Astrophysics · Physics 2009-11-11 F. J. Cao

Inflationary cosmology with a preceding nonsingular bounce can lead to changes on the primordial density fluctuations. One significant prediction is that the amplitude of the power spectrum may undergo a jump at a critical scale. In this…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-10 Jie Liu , Yi-Fu Cai , Hong Li

One of the fundamental problems of modern cosmology is to explain the origin of all the matter and radiation in the Universe today. The inflationary model predicts that the oscillations of the scalar field at the end of inflation will…

High Energy Physics - Phenomenology · Physics 2007-05-23 Juan Garcia-Bellido

We conduct a (pre-)inflationary dynamics study within the framework of a simple noncommutative extension of effective loop quantum cosmology -- put forward recently by the authors -- which preserves its key features (in particular, the…

General Relativity and Quantum Cosmology · Physics 2023-08-04 Luis Rey Díaz-Barrón , Abraham Espinoza-García , S. Pérez-Payán , J. Socorro

Loop quantum cosmology (LQC) predicts a nonsingular evolution of the universe through a bounce in the high energy region. We show that this is always true in tachyon matter LQC. Different from the classical Friedman-Robertson-Walker (FRW)…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hua-Hui Xiong , Jian-Yang Zhu

Inflation models can have an early phase of inflation where the evolution of the inflaton is driven by quantum fluctuations before entering the phase driven by the slope of the scalar field potential. For a Coleman-Weinberg potential this…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-06 Arjun Berera , Raghavan Rangarajan
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