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Related papers: Bianchi IX in the GUP approach

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The dynamics of the Bianchi IX cosmological model with minimally coupled massive real scalar field is studied. The possibility of non-singular transition from contraction to expansion is shown. A set of initial conditions that lead to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. V. Toporensky , V. O. Ustiansky

The isotropy and homogeneity of our Universe are the cardinal principles of modern cosmology built on the definition of metric through the prescription by Friedmann-Lema$\hat{i}$tre-Robertson-Walker (FLRW). From the aspects of geometry, the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-03 Jiwon Park , Sourav Mridha , Dukjae Jang , Mayukh R. Gangopadhyay , Myung-Ki Cheoun

In a viscous Bianchi type I metric of the Kasner form, it is well known that it is not possible to describe an anisotropic physical model of the universe, which satisfies the second law of thermodynamics and the dominant energy condition…

General Relativity and Quantum Cosmology · Physics 2009-10-31 M. Cataldo , S. del Campo , P. Salgado

It is believed that soon after the Planck time, Einstein's general relativity theory should be corrected to an effective quadratic theory. Numerical solutions for the anisotropic generalization of the Friedmann "open" model $H^ 3$ for this…

General Relativity and Quantum Cosmology · Physics 2012-04-11 Juliano A. de Deus , Daniel Müller

We consider a self-consistent system of Bianchi type-I (BI) gravitational field and a binary mixture of perfect fluid and dark energy. The perfect fluid is taken to be the one obeying the usual equation of state, i.e., $p = \zeta \ve$, with…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

We discuss the problem of the stability of the isotropy of the universe in the space of ever-expanding spatially homogeneous universes with a compact spatial topology. The anisotropic modes which prevent isotropy being asymptotically stable…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John D. Barrow , Hideo Kodama

In this work, we examine the dynamical aspects of the cosmological Mixmaster model within the framework of non-commutative generalized uncertainty principle (GUP) theories. The theory is formulated classically by introducing a well-defined…

General Relativity and Quantum Cosmology · Physics 2025-04-04 Sebastiano Segreto , Giovanni Montani

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

Stability analysis of the Bianchi type I universe in pure gravity theory is studied in details. We first derive the non-redundant field equation of the system by introducing the generalized Bianchi type I metric. This non-redundant equation…

High Energy Physics - Theory · Physics 2009-11-07 W. F. Kao

We investigate possible astronomical manifestations of space-time anisotropy. The homogeneous vacuum Kasner solution was chosen as a reference anisotropic cosmological model because there are no effects caused by inhomogeneity in this…

General Relativity and Quantum Cosmology · Physics 2023-05-30 S L Parnovsky

Following the recent recognition of a positive value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Paulo Aguiar , Paulo Crawford

In the Bianchi I cosmology some subclasses of the Horndeski theory allow for the non-standard anisotropy behavior. For example, the anisotropy is damped near the initial singularity instead of tending to infinity. In this article, we…

General Relativity and Quantum Cosmology · Physics 2022-12-27 Ruslan K. Muharlyamov , Tatiana N. Pankratyeva

In recent years, there have been increasing challenges to the cosmological principle, based on new observations of e.g. supernovae and the cosmic bulk flow. As a result, the cosmological community is speaking their concern for the…

General Relativity and Quantum Cosmology · Physics 2026-05-15 Robbert W. Scholtens , Marcello Seri , Holger Waalkens , Rien van de Weygaert

Models of a rotating universe have been studied widely since G{\"o}del \cite{1}, who showed an example that is consistent with General Relativity (GR). By now, the possibility of a rotating universe has been discussed comprehensively in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Shi-Chun Su , M. -C. Chu

Generalized second law of thermodynamics in the Bianchi type I universe with the generalized holographic Ricci dark energy model is studied in this paper. The behavior of dark energy's equation of state parameter indicates that it is…

General Relativity and Quantum Cosmology · Physics 2016-02-02 En-Kun Li , Yu Zhang , Jin-Ling Geng , Peng-Fei Duan

The implications of a Generalized Uncertainty Principle on the Taub cosmological model are investigated. The model is studied in the ADM reduction of the dynamics and therefore a time variable is ruled out. Such a variable is quantized in a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marco Valerio Battisti , Giovanni Montani

We analyze the semiclassical and quantum behavior of the Bianchi IX Universe in the Polymer Quantum Mechanics framework, applied to the isotropic Misner variable, linked to the space volume of the model. The study is performed both in the…

General Relativity and Quantum Cosmology · Physics 2018-11-06 Chiara Crinò , Giovanni Montani , Giorgio Pintaudi

Understanding the early evolution of the universe requires models that incorporate possible quantum and anisotropic effects in its dynamics. In this work, we analyze the dynamical evolution of locally rotationally symmetric anisotropic…

General Relativity and Quantum Cosmology · Physics 2025-10-13 G. Oliveira-Neto , Y. Soncco Apaza

We provide a quantum picture for the emergence of a bouncing cosmology, according to the idea that a semiclassical behavior of the Universe towards the singularity is not available in many relevant Minisuperspace models. In particular, we…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Eleonora Giovannetti , Giovanni Montani

We analyze the global dynamics of Bianchi type I solutions of the Einstein equations with anisotropic matter. The matter model is not specified explicitly but only through a set of mild and physically motivated assumptions; thereby our…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Simone Calogero , J. Mark Heinzle
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