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Related papers: Effective $f(R)$ actions for modified Loop Quantum…

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The closed, spatially isotropic FLRW universe (k=+1) is endowed with modifications due to a discrete underlying space-structure. Motivated from Loop Quantum Gravity techniques, a full Thiemann regularisation is performed. The impact of…

General Relativity and Quantum Cosmology · Physics 2021-03-22 Klaus Liegener , Stefan Andreas Weigl

We consider the matter bounce scenario in Loop Quantum Cosmology (LQC) for physical potentials that at early times provide a nearly matter dominated Universe in the contracting phase, having a reheating mechanism in the expanding phase,…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Jaume Haro , Jaume Amorós

Considering as usual that the underlying geometry of our universe is well described by the spatially flat Friedmann-Lemaitre-Robertson-Walker line element, we review how the background of holonomy corrected Loop Quantum Cosmology (LQC)…

General Relativity and Quantum Cosmology · Physics 2019-05-01 Jaume de Haro , Llibert Aresté Saló , Supriya Pan

General relativity predicts a singularity in the beginning of the universe being called big bang. Recent developments in loop quantum cosmology avoid the singularity and the big bang is replaced by a big bounce. A classical theory of…

General Physics · Physics 2011-02-08 Walter Petry

Modified gravity theories have the potential of explaining the recent acceleration of the Universe without resorting to the mysterious concept of dark energy. In particular, it has been pointed out that matter-geometry coupling may be…

General Relativity and Quantum Cosmology · Physics 2016-08-17 Min-Xing Xu , Tiberiu Harko , Shi-Dong Liang

It is known that in loop quantum cosmology (LQC) the universe avoids the singularity by a bounce when the matter density approaches the critical density $\rho_c$ (the order of Planck density). After incorporating the inverse volume…

General Relativity and Quantum Cosmology · Physics 2011-03-14 Hua-Hui Xiong , Jian-Yang Zhu

We find a simple modification of the longitudinal mode in General Relativity which incorporates the idea of limiting curvature. In this case the singularities in contracting Friedmann and Kasner universes are avoided, and instead, the…

General Relativity and Quantum Cosmology · Physics 2017-04-18 Ali H. Chamseddine , Viatcheslav Mukhanov

This study uses very simple symmetry and consistency considerations to put constraints on possible Friedmann equations for modified gravity models in curved spaces. As an example, it is applied to loop quantum cosmology.

General Relativity and Quantum Cosmology · Physics 2016-06-21 Linda Linsefors , Aurelien Barrau

In the path integral formulation of the reduced phase space Loop Quantum Gravity (LQG), we propose a new approach to allow the spatial cubic lattice (graph) to change dynamically in the physical time evolution. The equations of motion of…

General Relativity and Quantum Cosmology · Physics 2021-07-14 Muxin Han , Hongguang Liu

We compute second-order quantum corrections, as quantum dispersions and correlations, to a cosmological model coupling a single scalar perturbation mode to a bouncing background within Loop Quantum Cosmology (LQC). Using an effective…

General Relativity and Quantum Cosmology · Physics 2026-05-19 Héctor Hernández Hernández , Hugo Morales Técotl , Gustavo Sánchez Herrera

This paper analyses the cosmological consequences of a modified theory of gravity whose action integral is built from a linear combination of the Ricci scalar $R$ and a quadratic term in the covariant derivative of $R$. The resulting…

General Relativity and Quantum Cosmology · Physics 2015-12-31 R. R. Cuzinatto , C. A. M. de Melo , L. G. Medeiros , P. J. Pompeia

In this paper, we study the main cosmological properties of the classical Friedmann equations in the case of homogeneous and isotropic Friedmann-Robertson-Walker Universe and we also generalized the expression of the Friedmann equation in…

General Relativity and Quantum Cosmology · Physics 2014-03-13 S. Chattopadhyay , A. Ashurov , M. Khurshudyan , K. Myrzakulov , A. Pasqua , R. Myrzakulov

The detailed formulation for loop quantum cosmology (LQC) in the Bianchi I model with a massless scalar field was recently constructed. In this paper, its effective dynamics with the LQC discreteness corrections is studied and the equations…

General Relativity and Quantum Cosmology · Physics 2007-09-12 Dah-Wei Chiou

Since there are quantization ambiguities in constructing the Hamiltonian constraint operator in isotropic loop quantum cosmology, it is crucial to check whether the key features of loop quantum cosmology, such as the quantum bounce and…

General Relativity and Quantum Cosmology · Physics 2009-04-28 Jinsong Yang , You Ding , Yongge Ma

The global dynamics of a homogeneous universe in Loop Quantum Cosmology is viewed as a scattering process of its geometrodynamical equivalent. This picture is applied to build a flexible (easy to generalize) and not restricted just to…

General Relativity and Quantum Cosmology · Physics 2010-04-22 Wojciech Kaminski , Tomasz Pawlowski

In loop quantum cosmology (LQC) the big bang singularity is generically resolved by a big bounce. This feature holds even when modified quantization prescriptions of the Hamiltonian constraint are used such as in mLQC-I and mLQC-II. While…

General Relativity and Quantum Cosmology · Physics 2023-06-30 Adrià Delhom , Gonzalo J. Olmo , Parampreet Singh

We discuss how a cyclic model for the flat universe can be constructively derived from Loop Quantum Gravity. This model has a lower bounce, at small values of the scale factor, which shares many similarities with that of Loop Quantum…

General Relativity and Quantum Cosmology · Physics 2017-06-13 Francesco Cianfrani , Jerzy Kowalski-Glikman , Giacomo Rosati

It was shown recently that replacing classical geodesics with quantal (Bohmian) trajectories gives rise to a quantum corrected Raychaudhuri equation (QRE). In this article we derive the second order Friedmann equations from the QRE, and…

General Relativity and Quantum Cosmology · Physics 2015-01-16 Ahmed Farag Ali , Saurya Das

We derive the primordial power spectra and spectral indexes of the density fluctuations and gravitational waves in the framework of loop quantum cosmology (LQC) with holonomy and inverse-volume corrections, by using the uniform asymptotic…

General Relativity and Quantum Cosmology · Physics 2015-08-04 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng , Qiang Wu

Symmetric teleparallel gravity and its $f(Q)$ extensions have emerged as promising alternatives to General Relativity (GR), yet the role of explicit geometry-matter couplings remains largely unexplored. In this work, we address this gap by…

General Relativity and Quantum Cosmology · Physics 2025-09-22 Ayush Hazarika , Simran Arora , P. K. Sahoo , Tiberiu Harko
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