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In this paper we study dynamics of the closed FRW model with holonomy corrections coming from loop quantum cosmology. We consider models with a scalar field and cosmological constant. In case of the models with cosmological constant and…

General Relativity and Quantum Cosmology · Physics 2009-11-19 Jakub Mielczarek , Orest Hrycyna , Marek Szydlowski

The Hamiltonian constraint of scalar-tensor theories in the Jordan frame is quantised using three quantisation prescriptions in loop quantum cosmology, from which we obtain three different effective Hamiltonian constraints. The…

General Relativity and Quantum Cosmology · Physics 2022-12-08 Yu Han

In this paper we investigate dynamics of the modified loop quantum cosmology models using dynamical systems methods. Modifications considered come from the choice of the different field strength operator $\hat{F}$ and result in different…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Orest Hrycyna , Jakub Mielczarek , Marek Szydlowski

In this paper we study the flat (k=0) cosmological FRW model with holonomy corrections of Loop Quantum Gravity. The considered universe contains a massless scalar field and the cosmological constant Lambda. We find analytical solutions for…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jakub Mielczarek , Tomasz Stachowiak , Marek Szydlowski

An one-parameter regularization freedom of the Hamiltonian constraint for loop quantum gravity is analyzed. The corresponding spatially flat, homogenous and isotropic model includes the two well-known models of loop quantum cosmology as…

General Relativity and Quantum Cosmology · Physics 2021-11-12 Xiangdong Zhang , Gaoping Long , Yongge Ma

The dynamical behaviors of FRW Universe containing a posivive/negative potential scalar field in loop quantum cosmology scenario are discussed. The method of the phase-plane analysis is used to investigate the stability of the Universe. It…

General Relativity and Quantum Cosmology · Physics 2014-02-03 Xiao Liu , Kui Xiao , Jian-Yang Zhu

Despite its great successes in accounting for the current observations, the so called `standard' model of cosmology faces a number of fundamental unresolved questions. Paramount among these are those relating to the nature of the origin of…

General Relativity and Quantum Cosmology · Physics 2008-02-29 Martin Bojowald , Reza Tavakol

Working in Einstein frame we introduce, in order to avoid singularities, holonomy corrections to the $f(R)=R+\alpha R^2$ model. We perform a detailed analytical and numerical study when holonomy corrections are taken into account in both…

General Relativity and Quantum Cosmology · Physics 2014-05-14 J. Amorós , J. de Haro , S. D. Odintsov

In this paper, a new Hamiltonian constraint operator for loop quantum cosmology is constructed by using the Chern-Simons action. The quantum dynamics of the $k=0$ cosmological model with respect to a massless scalar field as an emergent…

General Relativity and Quantum Cosmology · Physics 2019-09-23 Jinsong Yang , Cong Zhang , Yongge Ma

The effective dynamics of scalar-tensor theory (STT) in the Jordan frame is studied in the context of loop quantum cosmology with holonomy corrections. After deriving the effective Hamiltonian from the connection dynamics formulation, we…

General Relativity and Quantum Cosmology · Physics 2020-01-01 Yu Han

The dynamical behaviors of interacting dark energy in loop quantum cosmology are discussed in this paper. Based on defining three dimensionless variables, we simplify the equations of the fixed points. The fixed points for interacting dark…

General Relativity and Quantum Cosmology · Physics 2011-02-15 Kui Xiao , Jian-Yang Zhu

Group field theory (GFT) models for quantum gravity coupled to a massless scalar field give rise to cosmological models that reproduce the (expanding or contracting) dynamics of homogeneous and isotropic spacetimes in general relativity at…

High Energy Physics - Theory · Physics 2023-07-27 Steffen Gielen , Robert Santacruz

An exactly solvable bounce model in loop quantum cosmology is identified which serves as a perturbative basis for realistic bounce scenarios. Its bouncing solutions are derived analytically, demonstrating why recent numerical simulations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald

We discuss dynamical systems approaches and methods applied to flat Robertson-Walker models in $f(R)$-gravity. We argue that a complete description of the solution space of a model requires a global state space analysis that motivates…

General Relativity and Quantum Cosmology · Physics 2016-09-07 Artur Alho , Sante Carloni , Claes Uggla

A new model is studied which describes the quantum behavior of transitions through an isotropic quantum cosmological bounce in loop quantum cosmology sourced by a free and massless scalar field. As an exactly solvable model even at the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald

We consider a dynamical system of phantom scalar field under exponential potential in background of loop quantum cosmology. In our analysis, there is neither stable node nor repeller unstable node but only two saddle points, hence no Big…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Daris Samart , Burin Gumjudpai

Semiclassical states in isotropic loop quantum cosmology are employed to show that the improved dynamics has the correct classical limit. The effective Hamiltonian for the quantum cosmological model with a massless scalar field is thus…

General Relativity and Quantum Cosmology · Physics 2009-02-27 You Ding , Yongge Ma , Jinsong Yang

We provide an analytical solution to the quantum dynamics of a flat Friedmann-Lema\^itre- Robertson-Walker model with a massless scalar field in the presence of a small and positive cosmological constant, in the context of Loop Quantum…

General Relativity and Quantum Cosmology · Physics 2020-02-06 Mercedes Martín-Benito , Rita B. Neves

The five-dimensional loop quantum Kaluza-Klein cosmology is constructed based on the symmetric reduction of the connection formulation of the full theory. Through semiclassical analysis, the effective scalar constraint for the cosmological…

General Relativity and Quantum Cosmology · Physics 2026-02-20 Shengzhi Li , Yongge Ma , Faqiang Yuan , Xiangdong Zhang

The scheme of using the Chern-Simons action to regularize the gravitational Hamiltonian constraint is extended to including the Lorentzian term in the $k=0$ cosmological model. The Euclidean term and the Lorenzian term are thus regularized…

General Relativity and Quantum Cosmology · Physics 2020-10-12 Jinsong Yang , Cong Zhang , Yongge Ma
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