English
Related papers

Related papers: Loop Quantum Cosmology: Physics of Singularity Res…

200 papers

The classical and quantum properties of a new solution obtained in $2+1$% -dimensional gravity coupled with a real scalar field is analyzed in detail. The considered new solution is a one-parameter generalization of a previously known…

General Relativity and Quantum Cosmology · Physics 2017-04-14 O. Gurtug , S. Habib Mazharimousavi , M. Halilsoy

The dynamics of a (3 + 1) dimensional homogeneous anisotropic universe is modified by Loop Quantum Cosmology and, consequently, it has generically a big bounce in the past instead of a big-bang singularity. This modified dynamics can be…

General Relativity and Quantum Cosmology · Physics 2016-11-11 S. Kalyana Rama

The spatially flat and isotropic cosmological model of Brans-Dicke theory with coupling parameter $\omega\neq-3/2$ is quantized by the approach of loop quantum cosmology. An interesting feature of this model is that, although the…

General Relativity and Quantum Cosmology · Physics 2013-04-16 Xiangdong Zhang , Michal Artymowski , Yongge Ma

We demonstrate how holonomy corrections in loop quantum cosmology (LQC) prevent the Big Rip singularity by introducing a quadratic modification in terms of the energy density $\rho$ in the Friedmann equation in the…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Kazuharu Bamba , Jaume de Haro , Sergei D. Odintsov

The standard $\Lambda$CDM model despite its agreement with observational data still has some issues unaddressed, lie the problem of initial singularity. Solving that problem usually requires modifications of general relativity. However,…

General Relativity and Quantum Cosmology · Physics 2023-03-29 Ewa Czuchry

The absence of isotropic singularity in loop quantum cosmology can be understood in an effective classical description as the universe exhibiting a Big Bounce. We show that with scalar matter field, the big bounce is generic in the sense…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Ghanashyam Date , Golam Mortuza Hossain

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 investigated the cosmology in a higher-curvature gravity where the dimensionality of spacetime gives rise to only quantitative difference, contrary to Einstein gravity. We found exponential type solutions for flat isotropic and…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Y. Ezawa , H. Iwasaki , M. Ohmori , S. Ueda , N. Yamada , T. Yano

We consider a renormalizable two-dimensional model of dilaton gravity coupled to a set of conformal fields as a toy model for quantum cosmology. We discuss the cosmological solutions of the model and study the effect of including the…

High Energy Physics - Theory · Physics 2009-10-22 F. D. Mazzitelli , J. G. Russo

Loop Quantum Gravity is a nonperturbative and background independent program for the quantization of General Relativity. Its underlying formalism has been applied successfully to the study of cosmological spacetimes, both to test the…

General Relativity and Quantum Cosmology · Physics 2021-09-13 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán

Degenerate geometrical configurations in quantum gravity are important to understand if the fate of classical singularities is to be revealed. However, not all degenerate configurations arise on an equal footing, and one must take into…

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

The classical singularity theorems of R. Penrose and S. Hawking from the 1960s show that, given a pointwise energy condition (and some causality as well as initial assumptions), spacetimes cannot be geodesically complete. Despite their…

General Relativity and Quantum Cosmology · Physics 2026-02-10 Melanie Graf , Eleni-Alexandra Kontou , Argam Ohanyan , Yasmin Schinnerl

The closed, k=1, FRW model coupled to a massless scalar field is investigated in the framework of loop quantum cosmology using analytical and numerical methods. As in the k=0 case, the scalar field can be again used as emergent time to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Abhay Ashtekar , Tomasz Pawlowski , Parampreet Singh , Kevin Vandersloot

Critical gravitational collapse offers a unique window into regimes of arbitrarily high curvature, culminating in a naked singularity arising from smooth initial data -- thus providing a dynamical counterexample to weak cosmic censorship.…

General Relativity and Quantum Cosmology · Physics 2026-05-18 Marija Tomašević , Chih-Hung Wu

In loop quantum cosmology (LQC) the big bang is replaced by a quantum bounce which is followed by a robust phase of super-inflation. Rather than growing unboundedly in the past, the Hubble parameter \emph{vanishes} at the bounce and attains…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Abhay Ashtekar , David Sloan

The existence of black holes in the Universe is nowadays established on the grounds of a blench of astrophysical observations, most notably those of gravitational waves from binary mergers and the imaging of supermassive objects at the…

General Relativity and Quantum Cosmology · Physics 2025-06-24 Haroldo C. D. Lima Junior , Renan B. Magalhães , Gonzalo J. Olmo , Diego Rubiera-Garcia

We investigate a cosmological model with a big-brake singularity in the future: while the first time derivative of the scale factor goes to zero, its second time derivative tends to minus infinity. Although we also discuss the classical…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alexander Kamenshchik , Claus Kiefer , Barbara Sandhoefer

We investigate the effect of higher-order curvature terms, specifically Gauss-Bonnet terms, on spacetime singularities in five dimensions. For FLRW cosmologies, we demonstrate that Gauss-Bonnet terms can replace the Big Bang/Crunch with a…

General Relativity and Quantum Cosmology · Physics 2026-02-24 Tariq Allaithy , Adel Awad , Mohamed Hany Radwan , Mohsen Zahran

Loop Quantum Cosmology (LQC) is a theory which renders the Big Bang initial singularity into a quantum bounce, by means of short range repulsive quantum effects at the Planck scale. In this work, we are interested in reproducing the…

General Relativity and Quantum Cosmology · Physics 2021-11-25 Marcello Miranda , Daniele Vernieri , Salvatore Capozziello , Francisco S. N. Lobo

Loop Quantum Gravity (LQG) is a theory that proposes a way to model the behavior of the spacetime in situations where its atomic characteristic arises. Among these situations, the spacetime behavior near the Big Bang or black hole's…

General Relativity and Quantum Cosmology · Physics 2019-03-08 M. B. Cruz , C. A. S. Silva , F. A. Brito