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Related papers: Loop Quantum Cosmology, Boundary Proposals, and In…

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Recently the mechanism was found which allows avoidance of the cosmological singularity within the semi-classical formulation of Loop Quantum Gravity. Numerical studies show that the presence of self-interaction potential of the scalar…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. V. Vereshchagin

The first aim of this lecture is to highlight two areas of recent progress in inflationary cosmology, namely reheating and the quantum theory of cosmological perturbations. The second aim is to discuss important conceptual problems for the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robert H. Brandenberger

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

In the recent years the quantization methods of Loop Quantum Gravity have been successfully applied to the homogeneous and isotropic Friedmann-Robertson-Walker space-times. The resulting theory, called Loop Quantum Cosmology (LQC), resolves…

General Relativity and Quantum Cosmology · Physics 2010-11-23 Michal Artymowski , Zygmunt Lalak , Lukasz Szulc

We consider warm inflation in the context of holographic cosmology. The weak and the strong dissipative regime are analysed in the slow-roll approximation and within what is known as intermediate inflation. For an appropriate choice of the…

High Energy Physics - Theory · Physics 2022-03-11 Zahra Bouabdallaoui , Ahmed Errahmani , Mariam Bouhmadi-López , Taoufik Ouali

The early stages of the universe evolution are discussed according to the hot big bang model and the grand unified theories. The shortcomings of big bang are summarized and their resolution by inflationary cosmology is sketched.…

High Energy Physics - Phenomenology · Physics 2008-11-26 George Lazarides

The Gowdy cosmologies provide a suitable arena to further develop Loop Quantum Cosmology, allowing the presence of inhomogeneities. For the particular case of Gowdy spacetimes with the spatial topology of a three-torus and a content of…

General Relativity and Quantum Cosmology · Physics 2010-09-22 L. J. Garay , M. Martín-Benito , G. A. Mena Marugán

Using the holographic entropy proposal for a closed universe by Verlinde, a bound on equations of state for different stages of the universe is obtained. Further exploring this bound, we find that an inflationary universe naturally emerges…

High Energy Physics - Theory · Physics 2007-05-23 Qing-Guo Huang

In light of the recent swampland conjectures, we explore quantum cosmology and eternal inflation beyond the slow roll regime. We consider a model of a closed universe with a scalar field $\phi$ in the framework of tunneling approach to…

General Relativity and Quantum Cosmology · Physics 2023-04-19 Georgios Fanaras , Alexander Vilenkin

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

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

We discuss applications of perturbative quantum gravity in the theory of very early quantum Universe and quantum cosmology. Consistency of the theoretical formalism for quantum effects of matter and correspondence with observational status…

High Energy Physics - Theory · Physics 2023-02-07 Andrei O. Barvinsky , Alexander Yu. Kamenshchik

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

The quantum evolution equation of Loop Quantum Cosmology (LQC) -- the quantum Hamiltonian constraint -- is a difference equation. We relate the LQC constraint equation in vacuum Bianchi I separable (locally rotationally symmetric) models…

General Relativity and Quantum Cosmology · Physics 2013-01-25 Christine C. Dantas

Possibly, the most general action in the background of isotropic and homogeneous space-time has been considered to study the quantum evolution of the early universe, apart from a cosmological constant. The hermiticity of the effective…

High Energy Physics - Theory · Physics 2020-10-30 Ranajit Mandal , Dalia Saha , Mohosin Alam , Abhik Kumar Sanyal

A model for a flat isotropic universe with a negative cosmological constant $\Lambda$ and a massless scalar field as sole matter content is studied within the framework of Loop Quantum Cosmology. By application of the methods introduced for…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Eloisa Bentivegna , Tomasz Pawlowski

We study the cosmological dynamics of non-minimally coupled matter models using the Brown's variational approach to relativistic fluids in General Relativity. After decomposing the Ricci scalar into a bulk and a boundary term, we construct…

General Relativity and Quantum Cosmology · Physics 2025-12-22 Hala A. Ashi , Christian G. Boehmer , Antonio d'Alfonso del Sordo , Erik Jensko

There is a wide consensus on the correct dynamics of the background in loop quantum cosmology. In this article we make a systematic investigation of the duration of inflation by varying what we think to be the most important "unknowns" of…

General Relativity and Quantum Cosmology · Physics 2017-04-19 Killian Martineau , Aurélien Barrau , Susanne Schander

The manner in which one approaches the interface between gravitation and quantum theory is influenced by one's posture regarding quantum mechanics and the issues that revolve about its interpretational problems. We discuss here the way in…

General Relativity and Quantum Cosmology · Physics 2025-02-11 Rosa-Laura Lechuga , Daniel Sudarsky

We quantize a homogeneous and isotropic universe for two models of modified teleparallel gravity, wherein an arbitrary function of the boundary term, namely $B$, is present in the action and in the other model a scalar field that is…

General Relativity and Quantum Cosmology · Physics 2024-05-07 H. Amiri , K. Atazadeh , H. Hadi