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Related papers: Tachyon field in Loop Quantum Cosmology: inflation…

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Warm inflation is analyzed in the context of Loop Quantum Cosmology (LQC). The bounce in LQC provides a mean through which a Liouville measure can be defined, which has been used previously to characterize the a priori probability for…

General Relativity and Quantum Cosmology · Physics 2018-08-01 L. L. Graef , Rudnei O. Ramos

The evolutions of the flat FLRW universe and its linear perturbations are studied systematically in the dressed metric approach of LQC. When it is dominated by the kinetic energy of the inflaton at the quantum bounce, the evolution of the…

General Relativity and Quantum Cosmology · Physics 2017-10-25 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng

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

The probability of there being sufficient inflation to solve the fine-tuning associated with the horizon and flatness problems has recently been shown to be exponentially small, within the context of classical general relativity. Here this…

General Relativity and Quantum Cosmology · Physics 2007-08-27 William Nelson

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

We present a detailed study of cosmological effects of homogeneous tachyon matter coexisting with non-relativistic matter and radiation, concentrating on the inverse square potential and the exponential potential for the tachyonic scalar…

Astrophysics · Physics 2011-05-05 J. S. Bagla , H. K. Jassal , T. Padmanabhan

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 systematically study the preinflationary dynamics of the spatially flat Friedmann-Lemaitre-Robertson-Walker universe filled with a single scalar field that has the generalized $\alpha-$attractor potentials, in the framework of loop…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-29 M. Shahalam , M. Sami , Anzhong Wang

We present a tachyonic field inflationary model in a teleparallel framework. We show that tachyonic coupled with the f(T) gravity model can describe the inflation era in which f(T) is an arbitrary function of torsion scalar T. For this…

General Relativity and Quantum Cosmology · Physics 2020-02-24 Amin Rezaei Akbarieh , Yousef Izadi

We discuss how initial conditions for cosmological evolution can be defined in Loop Quantum Cosmology with massive scalar field and how the presence of the bounce influences the probability of inflation in this theory, compared with General…

General Relativity and Quantum Cosmology · Physics 2019-02-15 Suzana Bedić , Gregory Vereshchagin

To understand mechanisms leading to inflation and late acceleration of the Universe it is important to see how one or a set of quantum fields may evolve such that the classical energy-momentum tensor behave similar to a cosmological…

General Relativity and Quantum Cosmology · Physics 2018-07-17 Houri Ziaeepour

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

Positively-curved, oscillatory universes are studied within the context of Loop Quantum Cosmology subject to a consistent semi-classical treatment. The semi-classical effects are reformulated in terms of an effective phantom fluid with a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 James E. Lidsey , David J. Mulryne , N. J. Nunes , Reza Tavakol

We consider curved space quantum corrections to the equations of motion of the inflaton field in the early Universe. Using the stochastic formalism in phase space, we demonstrate that the quantum corrected evolution of the inflaton can…

High Energy Physics - Phenomenology · Physics 2009-09-25 Zygmunt Lalak , Rudolf Poppe

Cosmology appears as the most promising way to test and constrain quantum gravity theories. Loop quantum gravity is among the most advanced attempts to perform a non-perturbative quantization of general relativity. Its cosmological…

General Relativity and Quantum Cosmology · Physics 2023-06-27 Killian Martineau

Using techniques from loop quantum gravity, the standard theory of cosmological perturbations was recently generalized to encompass the Planck era. We now apply this framework to explore pre-inflationary dynamics. The framework enables us…

General Relativity and Quantum Cosmology · Physics 2015-03-12 Ivan Agullo , Abhay Ashtekar , William Nelson

Recently, the tachyon cosmology has been represented as dark energy model to support the current acceleration of the universe without phantom crossing. In this paper, we study the dynamics of the tachyon cosmology in which the field plays…

General Relativity and Quantum Cosmology · Physics 2015-05-27 H. Farajollahi , A. Ravanpak , G. F. Fadakar

One possible description of the very early stages of the evolution of the universe is provided by Chaotic Inflationary Cosmology. For that model the role of the inflaton field is played by quantum gravitational effects. We study if such a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Pablo Mora

We study slow-roll inflation driven by a scalar field non-minimally coupled to gravity within the effective framework of Loop Quantum Cosmology (LQC), including inverse-volume corrections. We consider two physically motivated classes of…

General Relativity and Quantum Cosmology · Physics 2026-03-05 Rudranil Roy , Giovanni Otalora , Joel Saavedra , Salvatore Capozziello

The inflationary and pre-inflationary evolution of scalar modes of cosmological perturbations in a closed universe is analyzed for a loop quantum cosmology model with an inflationary regime consistent with the constraints on inflation…

General Relativity and Quantum Cosmology · Physics 2024-11-26 Lucas M. V. Montese , Nelson Yokomizo