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Related papers: Analogue models for FRW cosmologies

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We consider the problem of describing the asymptotic behaviour of \textsc{FRW} universes near their spacetime singularities in general relativity. We find that the Bel-Robinson energy of these universes in conjunction with the Hubble…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Spiros Cotsakis , Ifigeneia Klaoudatou

This introductory review is addressed to beginning researchers. Some of the distinguishing features of loop quantum gravity are illustrated through loop quantum cosmology of FRW models. In particular, these examples illustrate: i) how…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Abhay Ashtekar

One of the most well known relativistic field theory models is the Thirring model (TM). Its realization can demonstrate the famous prediction for the renormalization of mass due to interactions. However, experimental verification of the…

Quantum Physics · Physics 2013-03-22 Dimitris G. Angelakis , MingXia Huo , Darrick Chang , Leong Chuan Kwek , Vladimir Korepin

Recently, inhomogeneous generalisations of the Friedmann-Lemaitre-Robertson-Walker cosmological models have gained interest in the astrophysical community and are more often employed to study cosmological phenomena. However, in many papers…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-17 Krzysztof Bolejko , Marie-Noëlle Célérier , Andrzej Krasiński

We investigate the virialization of cosmic structures in the framework of flat FLRW cosmological models, in which the vacuum energy density evolves with time. In particular, our analysis focuses on the study of spherical matter…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 S. Basilakos , M. Plionis , J. Sola

The present paper deals with the dynamics of spatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological model with a time varying cosmological constant $\Lambda$ where $\Lambda$ evolves with the cosmic time (t) through the…

General Relativity and Quantum Cosmology · Physics 2022-10-19 Chingtham Sonia , S. Surendra Singh

We discuss FRW universe with time-dependent EoS dark fluid which leads to multiple de Sitter space. This model (as well as its scalar-tensor version) may be considered as some classical analog of cosmological landscape. The universe…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

We consider a cosmology in which a spherically symmetric large scale inhomogeneous enhancement or a void are described by an inhomogeneous metric and Einstein's gravitational equations. For a flat matter dominated universe the inhomogeneous…

Astrophysics · Physics 2008-11-26 J. W. Moffat

A range of cosmological observations demonstrate an accelerated expansion of the Universe, and the most likely explanation of this phenomenon is a cosmological constant. Given the importance of understanding the underlying physics, it is…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-07 Karoline Loeve , Kristine Simone Nielsen , Steen H. Hansen

We propose a model universe in the matter dominated phase described by a FRW background with local inhomogeneities, like our local patch, grown out of the primordial fluctuations. Our sub-horizon local patch consisting of different…

Astrophysics · Physics 2007-05-23 Reza Mansouri

General relativity uses curved space-time to describe accelerating frames. The movement of particles in different curved space-times can be regarded as equivalent physical processes based on the covariant transformation between different…

Optics · Physics 2018-10-24 Fan Zhong , Jensen Li , Hui Liu , Shining Zhu

The 3-space of a universe model is defined at a certain simultaneity. Hence space depends on which time is used. We find a general formula generating all known transformations to conformally flat spacetime coordinates, and work out the…

General Relativity and Quantum Cosmology · Physics 2011-03-25 Oyvind Gron , Steinar Johannesen

Observational evidence, together with practical computations and modeling, supports a Euclidean spatial sector in the current cosmological model based on the FLRW metric. This, however, would imply that the total amount of matter and energy…

General Relativity and Quantum Cosmology · Physics 2026-03-23 Gerardo García-Moreno , Bert Janssen , Alejandro Jiménez Cano , Marc Mars , Miguel Sánchez , Raül Vera

We study the evolution of linear cosmological perturbations in f(R) models of accelerated expansion in the physical frame where the gravitational dynamics are fourth order and the matter is minimally coupled. These models predict a rich and…

Astrophysics · Physics 2008-11-26 Yong-Seon Song , Wayne Hu , Ignacy Sawicki

We propose a cosmological model that describes isotropic expansion of inhomogeneous universe. The energy-momentum tensor that creates the spatial inhomogeneity may not affect the uniform expansion scaling factor $a(t)$ in the FLRW-like…

High Energy Physics - Theory · Physics 2014-10-15 Wei-Jian Geng , H. Lu

A phenomenological formalism is presented in which the apparent acceleration of the universe is generated by large-scale structure formation, thus eliminating the coincidence and magnitude fine-tuning problems of the Cosmological Constant…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Brett Bochner

A recently proposed Asymptotically Safe cosmology provides an elegant mechanism towards understanding the nature of dark energy and its associated cosmic coincidence problem. The underlying idea is that the accelerated expansion of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Fotios K. Anagnostopoulos , Spyros Basilakos , Georgios Kofinas , Vasilios Zarikas

We argue that standard tools of holography can be used to describe fully non-perturbative microscopic models of cosmology in which a period of accelerated expansion may result from the positive potential energy of time-dependent scalar…

High Energy Physics - Theory · Physics 2022-03-23 Stefano Antonini , Petar Simidzija , Brian Swingle , Mark Van Raamsdonk

In an open Friedmann-Robertson-Walker (FRW) space background, we study the classical and quantum cosmological models in the framework of the recently proposed nonlinear massive gravity theory. Although the constraints which are present in…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Babak Vakili , Nima Khosravi

We employ recently developed approximation methods in the hybrid quantization of the Gowdy $T^3$ model with linear polarization and a massless scalar field to obtain physically interesting solutions of this inhomogeneous cosmology. More…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Beatriz Elizaga Navascués , Mercedes Martín-Benito , Guillermo A. Mena Marugán