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We analyse the classical and quantum dynamics of a Bianchi I model in the presence of a small negative cosmological constant characterizing its evolution in term of the dust-time dualism. We demonstrate that in a canonical metric approach,…

General Relativity and Quantum Cosmology · Physics 2016-09-02 Riccardo Moriconi , Giovanni Montani , Salvatore Capozziello

We propose a quantum symmetry reduction of loop quantum gravity to Bianchi I spacetimes. To this end, we choose the diagonal metric gauge for the spatial diffeomorphism constraint at the classical level, leading to an…

General Relativity and Quantum Cosmology · Physics 2015-04-16 Norbert Bodendorfer

Due to non-perturbative quantum gravitational effects, the classical big bang singularity is replaced by a quantum big bounce of the mean scale factor in loop quantization of Bianchi-I spacetime. An important issue is to understand various…

General Relativity and Quantum Cosmology · Physics 2012-07-30 Brajesh Gupt , Parampreet Singh

We present the classical solutions to the Einstein field equations derived using the WKB-like and Hamilton procedures. The investigation is carried out in the commutative and noncommutative scenario for the Bianchi type I cosmological model…

General Relativity and Quantum Cosmology · Physics 2009-11-13 C. Ortiz , E. Mena-Barboza , M. Sabido , J. Socorro

We investigate the evolution of anisotropies in Bianchi I spacetimes within the framework of the 4D Einstein-Gauss-Bonnet scalar field theory. The field equations are formulated using dimensionless variables, and the asymptotic dynamics are…

General Relativity and Quantum Cosmology · Physics 2026-01-06 Alex Giacomini , Chevara Hansraj , Genly Leon , Andronikos Paliathanasis

We study numerically the solutions to the effective equations of Bianchi IX spacetimes within Loop Quantum Cosmology. We consider Bianchi IX models with and without inverse triad corrections whose matter content is a scalar field without…

General Relativity and Quantum Cosmology · Physics 2020-06-18 Alejandro Corichi , Edison Montoya

In this work, we examine the implications of $q$-deformed theory on anisotropic Bianchi type-I cosmological model within the framework of Verlinde's entropic gravity. The $q$-deformed theory, rooted in quantum group structures, provides a…

General Relativity and Quantum Cosmology · Physics 2025-02-05 Salih Kibaroğlu , Mustafa Senay

The loop quantum cosmology "improved dynamics" of the Bianchi type IX model are studied. The action of the Hamiltonian constraint operator is obtained via techniques developed for the Bianchi type I and type II models, no new input is…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Edward Wilson-Ewing

We numerically solve the effective loop quantum cosmology dynamics for the vacuum Bianchi type II and type IX spacetimes, in particular studying how the Kasner exponents evolve across the loop quantum cosmology bounce. We find that when the…

General Relativity and Quantum Cosmology · Physics 2023-10-11 Timothy Blackmore , Edward Wilson-Ewing

We investigate the classical and quantum behavior of a Bianchi I model in the presence of a stiff matter contribution when the Vilenkin interpretation of the wave function of the Universe is taken into account. We study its evolution in the…

General Relativity and Quantum Cosmology · Physics 2017-08-02 Riccardo Moriconi , Giovanni Montani

Within the framework of the minimum quadratic Poincare gauge theory of gravity in the Riemann-Cartan spacetime the dynamics of homogeneous anisotropic Bianchi types I-IX spinning-fluid cosmological models is investigated. A basic equation…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nguyen Hong Chuong , Nguyen Van Hoang

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

Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical…

General Relativity and Quantum Cosmology · Physics 2012-06-18 Suresh Kumar , Ozgur Akarsu

We study the dynamics of perturbations representing deviations from perfect isotropy in the context of the emergent cosmology obtained from the group field theory formalism for quantum gravity. Working in the mean field approximation of the…

General Relativity and Quantum Cosmology · Physics 2017-12-12 Marco de Cesare , Daniele Oriti , Andreas G. A. Pithis , Mairi Sakellariadou

We explore the isotropization of a model anisotropic universe in the bouncing models using the ekpyrotic potential without assuming initial conditions corresponding to an ekpyrotic phase. In particular, we explore the way the use of…

General Relativity and Quantum Cosmology · Physics 2025-12-11 Rachel Brown , A. Meenakshi McNamara , Sahil Saini , Parampreet Singh

The exact renormalization group flow equations for gravity lead to quantum corrections of Newton's constant and cosmological constant. Using this we investigate the Bianchi-I cosmological model at late times. In particular, we obtain the…

General Relativity and Quantum Cosmology · Physics 2022-08-11 Sunandan Gangopadhyay , Rituparna Mandal , Amitabha Lahiri

We use the vacuum Bianchi I model as an example to investigate the concept of physical evolution in Loop Quantum Cosmology (LQC) in the absence of the massless scalar field which has been used so far in the literature as an internal time.…

General Relativity and Quantum Cosmology · Physics 2009-11-05 Mercedes Martin-Benito , Guillermo A. Mena Marugan , Tomasz Pawlowski

We investigate the evolution of cosmological anisotropies within the framework of $f\left(G\right)$-gravity. Specifically, we consider a locally rotationally symmetric geometry in four-dimensional spacetime that describes the Bianchi I,…

General Relativity and Quantum Cosmology · Physics 2025-12-25 R. Bogadi , A. Giacomini , M. Govender , C. Hansraj , G. Leon , A. Paliathanasis

The effective quantum dynamics of Bianchi I spacetime is addressed within the statistical regularization scheme in Quantum Reduced Loop Gravity. The case of a minimally coupled massless scalar field is studied and compared with the…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Emanuele Alesci , Gioele Botta , Giovanni Luzi , Gabriele V. Stagno

A new class of a spatially homogeneous and anisotropic Bianchi type-I cosmological models of the universe for perfect fluid distribution within the framework of scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett.…

General Physics · Physics 2012-11-15 Anirudh Pradhan , Ajay Kumar Singh , H. Amirhashchi