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In this work numerical methods for solving Einstein's equations are developed and applied to the study of inhomogeneous cosmological models. A two-dimensional computer code is described which implements two advanced numerical methods:…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Simon D. Hern

Though loop quantization of several spacetimes has exhibited existence of a bounce via an explicit evolution of states using numerical simulations, the question about the way central singularity is resolved in the black hole interior has…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Alec Yonika , Gaurav Khanna , Parampreet Singh

Loop quantum cosmology, the symmetry reduction of quantum geometry for the study of various cosmological situations, leads to a difference equation for its quantum evolution equation. To ensure that solutions of this equation act in the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Daniel Cartin , Gaurav Khanna

Inhomogeneous quantum cosmology is modeled as a dynamical system of discrete patches, whose interacting many-body equations can be mapped to a non-linear minisuperspace equation by methods analogous to Bose-Einstein condensation.…

General Relativity and Quantum Cosmology · Physics 2012-12-18 Martin Bojowald , Alexander L. Chinchilli , Christine C. Dantas , Matthew Jaffe , David Simpson

Based on the observation that the exterior space-times of Schwarzschild-type solutions allow two symmetric slicings, a static spherically symmetric one and a timelike homogeneous one, modifications of gravitational dynamics suggested by…

General Relativity and Quantum Cosmology · Physics 2020-08-11 Martin Bojowald

This Chapter provides an up to date, pedagogical review of some of the most relevant advances in loop quantum cosmology. We review the quantization of homogeneous cosmological models, their singularity resolution and the formulation of…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Ivan Agullo , Alejandro Corichi

We continue the study of spherically symmetric vacuum space-times in loop quantum gravity by treating the interior of a black hole. We start from a midi-superspace approach, but a simple gauge fixing leads to a Kantowski--Sachs form for the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Miguel Campiglia , Rodolfo Gambini , Jorge Pullin

A quantum Schwarzschild spacetime and a quantum Schwarzschild-de Sitter spacetime with cosmological constant $\Lambda$ are constructed within the framework of a noncommutative Riemannian geometry developed in an earlier publication. The…

High Energy Physics - Theory · Physics 2009-04-17 Ding Wang , R. B. Zhang , Xiao Zhang

We present a new numerical scheme to treat the non-linear evolution of cosmological power spectra. Governing equations for matter power spectra have been previously derived by a non-perturbative technique with closure approximation.…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-30 Takashi Hiramatsu , Atsushi Taruya

We establish a new algorithm that generates a new solution to the Einstein field equations, with an anisotropic matter distribution, from a seed isotropic solution. The new solution is expressed in terms of integrals of an isotropic…

General Relativity and Quantum Cosmology · Physics 2014-11-17 M. Chaisi , S. D. Maharaj

Through averaging the Einstein equations over transverse gravitational perturbations it is obtained a closed system of two ordinary differential equations describing macroscopic cosmological evolution of the isotropic space-flat Universe…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Yurii Ignat'ev

It has been suggested that the homogeneous black hole interior spacetime, when quantized following the techniques of loop quantum cosmology, has a resolved singularity replaced by a black-to-white hole transition. This result has however…

General Relativity and Quantum Cosmology · Physics 2021-03-23 Francesco Sartini , Marc Geiller

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

The physical interpretation and eventual fate of gravitational singularities in a theory surpassing classical general relativity are puzzling questions that have generated a great deal of interest among various quantum gravity approaches.…

General Relativity and Quantum Cosmology · Physics 2019-11-06 Norbert Bodendorfer , Fabio M. Mele , Johannes Münch

This thesis describes the application of numerical techniques to solve Einstein's field equations in three distinct cases. First we present the first long-term stable second order convergent Cauchy characteristic matching code in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ulrich Sperhake

In "extended phase space" approach to quantum geometrodynamics numerical solutions to Schrodinger equation corresponding to various choice of gauge conditions are obtained for the simplest isotropic model. The "extended phase space"…

General Relativity and Quantum Cosmology · Physics 2008-01-31 T. P. Shestakova

In this article, we introduce a new effective model for the Kantowski-Sachs spacetime in the context of loop quantum gravity, and we use it to evaluate departures from general relativity in the case of Schwarzschild black hole interior. The…

General Relativity and Quantum Cosmology · Physics 2021-06-21 Mehdi Assanioussi , Lisa Mickel

We study the scalar modes of linear perturbations in loop quantum cosmology. This is done on a lattice where each cell is taken to be homogeneous and isotropic and can be quantized via standard homogeneous loop quantum cosmology techniques.…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Edward Wilson-Ewing

Inhomogeneities are introduced in loop quantum cosmology using regular lattice states, with a kinematical arena similar to that in homogeneous models considered earlier. The framework is intended to encapsulate crucial features of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald

In the last decade, progress on quantization of homogeneous cosmological spacetimes using techniques of loop quantum gravity has led to insights on various fundamental questions and has opened new avenues to explore Planck scale physics.…

General Relativity and Quantum Cosmology · Physics 2016-12-06 Ivan Agullo , Parampreet Singh