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Related papers: A quantum reduction to Bianchi I models in loop qu…

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We study a model for quantum gravity on a circle in which the notion of a classical metric tensor is replaced by a quantum metric with an inhomogeneous transformation law under diffeomorphisms. This transformation law corresponds to the…

General Relativity and Quantum Cosmology · Physics 2010-04-06 R. J. Henderson , S. G. Rajeev

This manuscript is devoted to investigate Bianchi Type $I$ universe in the context of $f(R,T)$ gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type $I$ spacetime. The modified field…

General Physics · Physics 2015-08-07 M. Farasat Shamir

We study the quantum dynamics of a supersymmetric squashed three-sphere by dimensionally reducing to one timelike dimension the action of D=4 simple supergravity for a Bianchi IX cosmological model. After imposition of the diffeomorphism…

General Relativity and Quantum Cosmology · Physics 2014-11-11 Thibault Damour , Philippe Spindel

We quantize spherically symmetric electrovacuum gravity. The algebra of Hamiltonian constraints can be made Abelian via a rescaling and linear combination with the diffeomorphism constraint. As a result the constraint algebra is a true Lie…

General Relativity and Quantum Cosmology · Physics 2015-04-16 Rodolfo Gambini , Esteban Mato Capurro , Jorge Pullin

By applying loop quantum gravity techniques to 3D gravity with a positive cosmological constant $\Lambda$, we show how the local gauge symmetry of the theory, encoded in the constraint algebra, acquires the quantum group structure of…

High Energy Physics - Theory · Physics 2016-12-09 Francesco Cianfrani , Jerzy Kowalski-Glikman , Daniele Pranzetti , Giacomo Rosati

Bianchi type III (BIII) metric is an interesting anisotropic model for studying cosmic anisotropy as it has an additional exponential term multiplied to a directional scale factor. Thus, the cosmological parameters obtained for this BIII…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Pranjal Sarmah , Umananda Dev Goswami

In this contribution we consider the issue of singularity resolution within loop quantum cosmology (LQC) for different homogeneous models. We present results of numerical evolutions of effective equations for both isotropic as well as…

General Relativity and Quantum Cosmology · Physics 2012-12-04 Alejandro Corichi , Asieh Karami , Edison Montoya

We investigate Bianchi I cosmological model in the theory of a dilatonM field coupled to gravity through a Gauss-Bonnet term. Two type ofM cosmological singularity are distinguished. The former is analogous toM the Einstein gravity…

General Relativity and Quantum Cosmology · Physics 2009-10-31 S. Alexeyev , A. Toporensky , V. Ustiansky

The general theory of N=1 supergravity with supermatter is applied to a Bianchi type IX diagonal model. The supermatter is constituted by a complex scalar field and its spin-$1\over 2$ fermionic partners. The K\"ahler geometry is chosen to…

General Relativity and Quantum Cosmology · Physics 2014-11-17 P. V. Moniz

We study homogeneous cosmological models in formulations of general relativity with cosmological constant based on a (complexified) connection rather than a spacetime metric, in particular in a first order theory obtained by integrating out…

General Relativity and Quantum Cosmology · Physics 2023-05-10 Steffen Gielen , Elliot Nash

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 "flat" model $E^3$ for this…

General Relativity and Quantum Cosmology · Physics 2012-04-02 Daniel Müller , Juliano A. de Deus

In the framework of loop quantum gravity, we define a new Hilbert space of states which are solutions of a large number of components of the diffeomorphism constraint. On this Hilbert space, using the methods of Thiemann, we obtain a family…

General Relativity and Quantum Cosmology · Physics 2015-03-05 Jerzy Lewandowski , Hanno Sahlmann

In this article, we study the equations driving the dynamics of a Bianchi-I universe described by holonomy corrected effective loop quantum cosmology. We derive the LQC-modified generalized Friedmann equation, which is used as a guide to…

General Relativity and Quantum Cosmology · Physics 2014-07-28 Linda Linsefors , Aurelien Barrau

We study the late-time evolution of an anisotropic Bianchi-I universe with radiation in the framework of asymptotically safe gravity. We first discuss the radiation-dominated universe for the perfect fluid with the equation of state…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Chiang-Mei Chen , Ting-Kui Fan , Rituparna Mandal , Nobuyoshi Ohta

We can solve the Wheeler-DeWitt equation of the enlarged Bianchi I as inhomogeneous type universe with static restriction which had been derived by previous paper. We consider the commutation relation between the static restriction and the…

General Relativity and Quantum Cosmology · Physics 2008-11-28 Shintaro Sawayama

We examine the dynamical consequences of homogeneous cosmological magnetic fields in the framework of loop quantum cosmology. We show that a big-bounce occurs in a collapsing magnetized Bianchi I universe, thus extending the known cases of…

General Relativity and Quantum Cosmology · Physics 2008-12-11 Roy Maartens , Kevin Vandersloot

The mathematically correct approach to constructing quantum geometrodynamics of a closed universe formulated in Part I is realized on the cosmological Bianchi-IX model with scalar fields. The physical adequacy of the obtained…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. A. Savchenko , T. P. Shestakova , G. M. Vereshkov

The preceding talks given at this conference have dealt mainly with general ideas for, main problems of and techniques for the task of quantizing gravity canonically. Since one of the major motivations to arrange for this meeting was that…

General Relativity and Quantum Cosmology · Physics 2015-06-25 T. Thiemann

Quantum Reduced Loop Gravity is a promising framework for linking Loop Quantum Gravity and the effective semiclassical dynamics of Loop Quantum Cosmology. We review its basic achievements and its main perspectives, outlining how it provides…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Emanuele Alesci , Francesco Cianfrani

We discuss the question of time in a Bianchi I quantum cosmology in the framework of singularity avoidance. We show that time parameters fall into two distinct classes, that are such that the time development of the wave function either…

General Relativity and Quantum Cosmology · Physics 2020-02-18 Przemyslaw Malkiewicz , Patrick Peter , S. D. P. Vitenti