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Related papers: Lemaitre-Tolman-Bondi collapse from the perspectiv…

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Quantum gravity is expected to remove the classical singularity that arises as the end-state of gravitational collapse. To investigate this, we work with a toy model of a collapsing homogeneous scalar field. We show that non-perturbative…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald , Rituparno Goswami , Roy Maartens , Parampreet Singh

We consider the vacuum gravitational collapse for cohomogeneity-two solutions of the nine dimensional Einstein equations. Using combined numerical and analytical methods we give evidence that within this model the Schwarzschild-Tangherlini…

General Relativity and Quantum Cosmology · Physics 2009-11-11 P. Bizoń , T. Chmaj , A. Rostworowski , B. G. Schmidt , Z. Tabor

Marginal LTB models with corrections from loop quantum gravity have recently been studied with an emphasis on potential singularity resolution. This paper corroborates and extends the analysis in two regards: (i) the whole class of LTB…

General Relativity and Quantum Cosmology · Physics 2009-11-06 Martin Bojowald , Juan D. Reyes , Rakesh Tibrewala

New general spherically symmetric solutions have been derived with a cosmological "constant" \Lambda as a source. This \Lambda field is not constant but it satisfies the properties of the asymptotically safe gravity at the ultraviolet fixed…

High Energy Physics - Theory · Physics 2023-09-26 Georgios Kofinas , Vasilios Zarikas

A debate has appeared in the literature on loop quantum gravity and spin foams, over whether the secondary simplicity constraints, reducing the connection to be Levi-Civita, should imply the shape matching conditions, reducing twisted…

General Relativity and Quantum Cosmology · Physics 2015-09-30 Fabio Anzà , Simone Speziale

The fate of matter forming a black hole is still an open problem, although models of quantum gravity corrected black holes are available. In loop quantum gravity (LQG) models were presented, which resolve the classical singularity in the…

General Relativity and Quantum Cosmology · Physics 2021-08-17 Johannes Münch

We study the quantization of spherically symmetric vacuum spacetimes within loop quantum gravity. In particular, we give additional details about our previous work in which we showed that one could complete the quantization the model and…

General Relativity and Quantum Cosmology · Physics 2016-12-20 Rodolfo Gambini , Javier Olmedo , Jorge Pullin

We explore the extension of quantum cosmology outside the homogeneous approximation, using the formalism of loop quantum gravity. We introduce a model where some of the inhomogeneous degrees of freedom are present, providing a tool for…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Carlo Rovelli , Francesca Vidotto

We describe a non-perturbative approach to studying the gravitational collapse of a scalar field in spherical symmetry with quantum gravity corrections. Quantum effects are described by a phase space function that modifies the constraints…

General Relativity and Quantum Cosmology · Physics 2011-09-15 Andreas Kreienbuehl , Viqar Husain , Sanjeev S. Seahra

We consider spherically symmetric gravity coupled to a spherically symmetric scalar field with a specific coupling which depends on the Areal Radius. Classical collapse is described by the Vaidya solution. The semiclassical Einstein…

General Relativity and Quantum Cosmology · Physics 2024-10-28 Madhavan Varadarajan

We consider spherically symmetric black holes in generic Lovelock gravity. Using geometrodynamical variables we do a complete Hamiltonian analysis, including derivation of the super-Hamiltonian and super-momentum constraints and…

General Relativity and Quantum Cosmology · Physics 2014-08-13 Gabor Kunstatter , Hideki Maeda , Tim Taves

We show that under certain technical assumptions, including the existence of a constant mean curvature (CMC) slice and strict positivity of the scalar field, general relativity conformally coupled to a scalar field can be quantised on a…

General Relativity and Quantum Cosmology · Physics 2013-04-25 Norbert Bodendorfer , Alexander Stottmeister , Andreas Thurn

The effective dynamics of loop quantum gravity for marginally bound Lema\^itre-Tolman-Bondi spacetimes predict that the big-bang singularity is resolved and replaced by a cosmic bounce. Numerics show that these effective dynamics also…

General Relativity and Quantum Cosmology · Physics 2025-03-12 Edward Wilson-Ewing

For a system with a Hamiltonian constraint, we demonstrate that its dynamics is invariant under different choices of the lapse function, regardless of whether the Hamiltonian incorporates quantum corrections. Applying this observation to…

General Relativity and Quantum Cosmology · Physics 2025-03-31 Zhong-Wen Feng , Qing-Quan Jiang , Yi Ling , Xiao-Ning Wu , Zhangping Yu

We present the state of the art regarding the relation between the physics of Quantum Black Holes and Noncommutative Geometry. We start with a review of models proposed in the literature for describing deformations of General Relativity in…

High Energy Physics - Theory · Physics 2014-11-18 Piero Nicolini

Lemaitre-Tolman-Bondi (LTB) solutions are used frequently to describe the collapse or expansion of spherically symmetric inhomogeneous mass distributions in the Universe. These exact solutions are obtained in the synchronous gauge where…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Karel Van Acoleyen

Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e. the fact that the backward evolution…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Martin Bojowald

Spherically symmetric models of loop quantum gravity have been studied recently by different methods that aim to deal with structure functions in the usual constraint algebra of gravitational systems. As noticed by Gambini and Pullin, a…

General Relativity and Quantum Cosmology · Physics 2015-09-09 Martin Bojowald , Suddhasattwa Brahma , Juan D. Reyes

We investigate conformally coupled quantum matter fields on spherically symmetric, continuously self-similar backgrounds. By exploiting the symmetry associated with the self-similarity the general structure of the renormalized quantum…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Patrick R Brady , Adrian C Ottewill

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