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Related papers: The Bianchi IX model in Loop Quantum Cosmology

200 papers

The structure of the Cauchy Horizon singularity of a black hole formed in a generic collapse is studied by means of a renormalization group equation for quantum gravity. It is shown that during the early evolution of the Cauchy Horizon the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Alfio Bonanno , Martin Reuter

Most of the potential physical effects of loop quantum gravity have been derived in effective models that modify the constraints of canonical general relativity in specific forms. Emergent modified gravity evaluates important conditions…

General Relativity and Quantum Cosmology · Physics 2025-05-01 Idrus Husin Belfaqih , Martin Bojowald , Suddhasattwa Brahma , Erick I. Duque

The occurrence of singularities where spacetime curvature becomes infinite and geodesic evolution breaks down are inevitable events in classical general relativity (GR) unless one chooses an exotic matter violating weak energy condition.…

General Relativity and Quantum Cosmology · Physics 2024-11-05 Bao-Fei Li , Parampreet Singh

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

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

Lemaitre-Tolman-Bondi models as specific spherically symmetric solutions of general relativity simplify in their reduced form some of the mathematical ingredients of black hole or cosmological applications. The conditions imposed in…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Tomohiro Harada , Rakesh Tibrewala

We investigate the interior structure, perturbations, and the associated quasinormal modes of a quantum black hole model recently proposed by Bodendorfer, Mele, and M\"unch (BMM). Within the framework of loop quantum gravity, the quantum…

General Relativity and Quantum Cosmology · Physics 2020-08-04 Mariam Bouhmadi-López , Suddhasattwa Brahma , Che-Yu Chen , Pisin Chen , Dong-han Yeom

We investigate the occurrence of various exotic spacelike singularities in the past and the future evolution of $k = \pm 1$ Friedmann-Robertson-Walker model and loop quantum cosmology using a sufficiently general phenomenological model for…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Parampreet Singh , Francesca Vidotto

We analyze the loop quantization of the family of vacuum Bianchi I spacetimes, a gravitational system whose classical solutions describe homogeneous anisotropic cosmologies. We rigorously construct the operator that represents the…

General Relativity and Quantum Cosmology · Physics 2009-02-20 M. Martin-Benito , G. A. Mena Marugan , T. Pawlowski

Studying Yang-Mills field and gravitational field in class A Bianchi spacetimes, we find that chaotic behavior appears in the late phase (the asymptotic future). In this phase, the Yang-Mills field behaves as that in Minkowski spacetime, in…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Yoshida Jin , Kei-ichi Maeda

We discuss the way non-perturbative quantization of cosmological spacetimes in loop quantum cosmology provides insights on the physics of Planck scale and the resolution of big bang singularity. In recent years, rigorous examination of…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Parampreet Singh

We analyze the Bianchi IX Universe in the Polymer Quantum Mechanics framework by facing both semiclassical and purely quantum effects near the cosmological singularity. We adopt Misner variables to describe the model dynamics, applying the…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Eleonora Giovannetti , Giovanni Montani

We find a supersymmetrization of the Bianchi IX cosmology in terms of Ashtekar's new variables. This provides a framework for connecting the recent results of Graham and those of Ryan and Moncrief for quantum states of this model. These…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Octavio Obregon , Jorge Pullin , Michael P. Ryan

Quantum effects are expected to modify the cosmological dynamics of the early universe while maintaining some (potentially discrete) notion of space-time structure. In one approach, loop quantum cosmology, current models are shown here to…

General Relativity and Quantum Cosmology · Physics 2026-04-29 Martin Bojowald , Manuel Diaz , Erick I. Duque

We develop the "triangulated" version of loop quantum cosmology, recently introduced in the literature. We focus on the "dipole" cosmology, where space is a three-sphere and the triangulation is formed by two tetrahedra. We show that the…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Marco Valerio Battisti , Antonino Marciano , Carlo Rovelli

The implications of the SU(2) gauge fixing associated with the choice of invariant triads in Loop Quantum Cosmology are discussed for a Bianchi I model. In particular, via the analysis of Dirac brackets, it is outlined how the holonomy-flux…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Francesco Cianfrani , Andrea Marchini , Giovanni Montani

In one-loop string effective action, we study a generality of non-singular cosmological solutions found in the isotropic and homogeneous case. We discuss Bianchi I and IX type spacetimes. We find that nonsingular solutions still exist in…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Hiroki Yajima , Kei-ichi Maeda , Hidetoshi Ohkubo

Nonlinear modifications of quantum theory are considered potential candidates for the theory of quantum gravity, with the intuitive argument that since Einstein field equations are nonlinear, quantum gravity should be nonlinear as well.…

Quantum Physics · Physics 2025-06-06 Ruben Campos Delgado , Martin Plávala

A consistent combination of quantum geometry effects rules out a large class of models of loop quantum cosmology and their critical densities as they have been used in the recent literature. In particular, the critical density at which an…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Martin Bojowald

We investigate the behaviour on approach to the initial singularity in higher-order extensions of general relativity by finding exact cosmological solutions for a wide class of models in which the Lagrangian is allowed to depend nonlinearly…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Jonathan Middleton