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Related papers: A quantum gravity extension to the Mixmaster dynam…

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We analyze the quantum dynamics of the Bianchi Type IX model, as described in the so-called polymer representation of quantum mechanics, to characterize the modifications that a discrete na- ture in the anisotropy variables of the Universe…

General Relativity and Quantum Cosmology · Physics 2013-12-24 Orchidea Maria Lecian , Giovanni Montani , Riccardo Moriconi

We investigate the $\phi^2$ inflationary model in the Bianchi-I spacetime using effective spacetime description of loop quantum cosmology to understand the issues of the resolution of initial singularity, isotropization, effect of…

General Relativity and Quantum Cosmology · Physics 2013-07-11 Brajesh Gupt , Parampreet Singh

We study the anisotropic Bianchi I loop quantum cosmology in 2+1 dimensions. Both the $\mubar$ and $\mubar'$ schemes are considered in the present paper and the following expected results are established: (i) the massless scalar field again…

General Relativity and Quantum Cosmology · Physics 2020-10-23 You Ding , Xiangdong Zhang

We study the effective cosmological dynamics, emerging as the hydrodynamics of simple condensate states, of a group field theory model for quantum gravity coupled to a massless scalar field and reduced to its isotropic sector. The quantum…

General Relativity and Quantum Cosmology · Physics 2016-11-23 Daniele Oriti , Lorenzo Sindoni , Edward Wilson-Ewing

We investigate the effective quantum evolution of the Bianchi type I cosmological model within the Brans-Dicke framework, using an effective Hamiltonian approach including expectation values, quantum dispersions, and cross-correlation terms…

General Relativity and Quantum Cosmology · Physics 2026-04-06 Hector Hugo Hernandez Hernandez , Gustavo Alejandro Sanchez Herrera

Within the framework of loop quantum cosmology, there exists a semi-classical regime where spacetime may be approximated in terms of a continuous manifold, but where the standard Friedmann equations of classical Einstein gravity receive…

General Relativity and Quantum Cosmology · Physics 2009-11-10 James E. Lidsey

We present a reformulation of the canonical quantization of gravity, as referred to the minisuperspace; the new approach is based on fixing a Gaussian (or synchronous) reference frame and then quantizing the system via the reconstruction of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Giovanni Montani

In classical Bianchi-I spacetimes, underlying conditions for what dictates the singularity structure - whether it is anisotropic shear or energy density, can be easily determined from the generalized Friedmann equation. However, in…

General Relativity and Quantum Cosmology · Physics 2022-12-29 A. Meenakshi McNamara , Sahil Saini , Parampreet Singh

A quantum analysis of the vacuum Bianchi IX model is performed, focusing in particular on the chaotic nature of the system. The framework constructed here is general enough for the results to apply in the context of any theory of quantum…

General Relativity and Quantum Cosmology · Physics 2024-04-17 Martin Bojowald , David Brizuela , Paula Calizaya Cabrera , Sara F. Uria

In this paper we analyse the Bianchi IX Universe dynamics within the corner region associated to the potential term which the spatial curvature induces in the Minisuperspace. The study is done in the vacuum and in the presence of a massless…

General Relativity and Quantum Cosmology · Physics 2020-10-21 Roberta Chiovoloni , Giovanni Montani , Valerio Cascioli

We present a review on basic aspects of quantum cosmology in the presence of cut-off physics. We first analyze how the Wheeler-DeWitt equation in a pure metric approach describes the quantum Universe, showing how the singularity is not…

General Relativity and Quantum Cosmology · Physics 2021-09-20 Gabriele Barca , Eleonora Giovannetti , Giovanni Montani

We study the anisotropic Bianchi type-I cosmological model at late times, taking into account quantum gravitational corrections in the formalism of the exact renormalization group flow of the effective average action for gravity. The…

General Relativity and Quantum Cosmology · Physics 2020-02-24 Rituparna Mandal , Sunandan Gangopadhyay , Amitabha Lahiri

We analyze the Bianchi I cosmology in the presence of a massless scalar field and describe its dynamics via a semiclassical and quantum polymer approach. We investigate the morphology of the emerging Big Bounce by adopting three different…

General Relativity and Quantum Cosmology · Physics 2022-03-10 Eleonora Giovannetti , Giovanni Montani , Silvia Schiattarella

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmological string is considered. The first objective of this study is to investigate Einstein equations using a tractable assumption usually accepted in the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Victor Rikhvitsky , Bijan Saha , Mihai Visinescu

We study anisotropic Bianchi-I cosmology, incorporating quantum gravitational corrections into the Einstein equation through the scale-dependent Newton coupling and cosmological term, as determined by the flow equation of the effective…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Chiang-Mei Chen , Akihiro Ishibashi , Rituparna Mandal , Nobuyoshi Ohta

We present a systematic study of the cosmological dynamics resulting from an effective Hamiltonian, recently derived in loop quantum gravity using Thiemann's regularization and earlier obtained in loop quantum cosmology (LQC) by keeping the…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Bao-Fei Li , Parampreet Singh , Anzhong Wang

The canonical quantization of the most general minisuperspace actions --i.e. with all six scale factor as well as the lapse function and the shift vector present-- describing the vacuum type II, VI and VII geometries, is considered. The…

General Relativity and Quantum Cosmology · Physics 2017-02-08 T. Christodoulakis , G. O. Papadopoulos

The primary aim of this work is to explore feasible bouncing cosmological solutions in the framework of $f(\mathcal{Q}, \mathcal{C})$ gravity, where $\mathcal{Q}$ denotes non-metricity and $\mathcal{C}$ indicates the boundary term. To…

General Relativity and Quantum Cosmology · Physics 2025-08-12 M. Sharif , M. Zeeshan Gul , Ahmad Nawaz

In this work we analyze the evolution of the quantum Mixmaster cosmological model within an effective approach. In particular, we study the behaviour of the scale factor and anisotropies of the theory, and determine how it deviates from its…

General Relativity and Quantum Cosmology · Physics 2024-01-09 Héctor Hugo Hernández Hernández , Gustavo Alejandro Sánchez Herrera

Loop quantum cosmology predicts that, in simple models, the big bang singularity of classical general relativity is replaced by a quantum bounce. Because of the extreme physical conditions near the bounce, a natural question is whether the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alejandro Corichi , Parampreet Singh