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Related papers: On non-singular inhomogeneous cosmological models

200 papers

We review recent work and present new examples about the character of singularities in globally and regularly hyperbolic, isotropic universes. These include recent singular relativistic models, tachyonic and phantom universes as well as…

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

We consider the general orthogonal metric separable in space and time variables in comoving coordinates. We then characterise perfect fluid models admitted by such a metric. It turns out that the homogeneous models can only be either FLRW…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Naresh Dadhich , L. K. Patel , K. S. Govinder , P. G. L. Leach

We investigate future singularities originating from the anisotropy in the Universe. We formulate a new class of singularities in the homogeneous and anisotropic universe, comparing them with the known singularities in the homogeneous and…

General Relativity and Quantum Cosmology · Physics 2024-09-09 Taishi Katsuragawa , Shin'ichi Nojiri , Sergei D. Odintsov

Recent progress in understanding the structure of cosmological singularities is reviewed. The well-known picture due to Belinskii, Khalatnikov and Lifschitz (BKL) is summarized briefly and it is discussed what existing analytical and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alan D. Rendall

A matter bouncing entropy-corrected cosmological model has been suggested. The model allows only positive curvature with negative pressure and no violation of the null energy condition. The result obtained in this paper is supported by some…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Nasr Ahmed , Tarek M. Kamel , Mohamed I Nouh

We present a class of singularity free exact cosmological solutions of Einstein's equations describing a perfect fluid with heat flow. It is obtained as generalization of the Senovilla class [1] corresponding to incoherent radiation field.…

General Relativity and Quantum Cosmology · Physics 2010-04-06 L. K. Patel , Naresh Dadhich

One of the fundamental assumptions of the standard $\Lambda$CDM cosmology is that, on large scales, all the matter-energy components of the Universe share a common rest frame. This seems natural for the visible sector, that has been in…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 J. A. R. Cembranos , A. L. Maroto , H. Villarrubia-Rojo

We investigate the robustness of some recent results obtained for homogeneous and isotropic cosmological models with conformally coupled scalar fields. For this purpose, we investigate anisotropic homogeneous solutions of the models…

General Relativity and Quantum Cosmology · Physics 2009-11-07 L. Raul Abramo , Leon Brenig , Edgard Gunzig , Alberto Saa

The purpose of this paper is to further investigate the solution space of self-similar spherically symmetric perfect-fluid models and gain deeper understanding of the physical aspects of these solutions. We achieve this by combining the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 B. J. Carr , A. A. Coley , M. Goliath , U. S. Nilsson , C. Uggla

We will describe here the structure of singularity forming in gravitational collapse of spherically symmetric inhomogeneous dust. Such a collapse is described by the Tolman-Bondi-Lema{\^i}tre metric. The main new result here relates, in a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Jhingan

Numerical simulations of the approach to the singularity in vacuum spacetimes are presented here. The spacetimes examined have no symmetries and can be regarded as representing the general behavior of singularities. It is found that the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 David Garfinkle

The discovery of universe's late-time acceleration and dark energy has overseen a great deal of research into cosmological singularities and in this brief review, we discuss all the prominent developments in this field for the best part of…

General Relativity and Quantum Cosmology · Physics 2024-08-02 Oem Trivedi

In the present letter, we consider homogeneous and isotropic noncommutative cosmological models induced by a symplectic formalism coupled to phantom perfect fluids and a cosmological constant. After computing the field equations, we solve…

General Relativity and Quantum Cosmology · Physics 2020-01-08 G. Oliveira-Neto , L. G. Rezende Rodrigues

The singularity structure of cosmological models whose matter content consists of a scalar field with arbitrary non-negative potential is discussed. The special case of spatially flat FRW space-time is analysed in detail using a dynamical…

General Relativity and Quantum Cosmology · Physics 2009-10-31 S. Foster

In addition to shear and vorticity a homogeneous background may also exhibit anisotropic curvature. Here a class of spacetimes is shown to exist where the anisotropy is solely of the latter type, and the shear-free condition is supported by…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Tomi S. Koivisto , David F. Mota , Miguel Quartin , Tom G. Zlosnik

The current standard model of cosmology, the LambdaCDM model, is based on the homogeneous FLRW solutions of the Einstein equations to which some perturbations are added to account for the CMB features and structure formation at large…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-14 Marie-Noëlle Célérier

Some remarkable examples of alternative cosmological theories are reviewed here, ranging from a compilation of variations on the Standard Model through the more distant quasi-steady-state cosmology, plasma cosmology, or universe models as a…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-17 Martin Lopez-Corredoira , Louis Marmet

In this paper we present a class of exact inhomogeneous solutions to Einstein's equations for higher dimensional Szekeres metric with perfect fluid and a cosmological constant. We also show particular solutions depending on the choices of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Subenoy Chakraborty , Ujjal Debnath

Higher-dimensional braneworld models which contain both bulk and brane curvature terms in the action admit cosmological singularities of rather unusual form and nature. These `quiescent' singularities, which can occur both during the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Yuri Shtanov , Varun Sahni

Recent studies of homogeneous anisotropic universe models in the brane world scenario show that the cosmological singularity in this context is isotropic. It has therefore been suggested that this may be a generic feature of singularities…

High Energy Physics - Theory · Physics 2009-11-07 Marco Bruni , Peter K. S. Dunsby