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Related papers: Exact nonlinear inhomogeneities in $\Lambda$CDM co…

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We use null spherical (observational) coordinates to describe a class of inhomogeneous cosmological models. The proposed cosmological construction is based on the observer past null cone. A known difficulty in using inhomogeneous models is…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Mustapha Ishak

Dust attenuation of an inclined galaxy can cause additional asymmetries in observations, even if the galaxy has a perfectly symmetric structure. {Taking advantage of the integral field spectroscopic data observed by the SDSS-IV MaNGA…

Astrophysics of Galaxies · Physics 2021-05-05 Fang-Ting Yuan , Jiafeng Lu , Shiyin Shen , Médéric Boquien

Gravitational lensing and stellar dynamics provide two complementary, nearly orthogonal, constraints on the mass distribution of early-type lens galaxies. This allows the luminous and dark-matter distribution in higher-redshift (z>0.1)…

Astrophysics · Physics 2007-05-23 L. V. E. Koopmans

In the standard approach to studying cosmological structure formation, the overall expansion of the Universe is assumed to be homogeneous, with the gravitational effect of inhomogeneities encoded entirely in a Newtonian potential. A topic…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 William E. East , Radosław Wojtak , Tom Abel

The growth of large-scale structure, together with the geometrical information of cosmic expansion history and cosmological distances, can be used to obtain constraints on the spatial curvature of the universe that probes the early universe…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-23 Ryo Terasawa , Ryuichi Takahashi , Takahiro Nishimichi , Masahiro Takada

The tensions between the values of Hubble constant obtained from the early and the late Universe data pose a significant challenge to modern cosmology. Possible modifications of the flat homogeneous isotropic cosmological {\Lambda}CDM model…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-14 S. L. Parnovsky

We evaluate the effect of inhomogeneity energy on the expansion rate of the universe. Our method is to expand to Newtonian order in potential and velocity but to take into account fully nonlinear density inhomogeneities. To linear order in…

Astrophysics · Physics 2009-11-11 E. R. Siegel , J. N. Fry

Using a gauge-invariant formalism we derive and solve the perturbed cosmological equations for the BSBM theory of varying fine structure 'constant'. We calculate the time evolution of inhomogeneous perturbations of the fine structure…

General Relativity and Quantum Cosmology · Physics 2009-11-07 John D. Barrow , D. F. Mota

The two-point correlation function for the dust distribution in the unperturbed Einstein-de Sitter cosmological model is studied along the past light cone. It was found that this function seems unable to represent the theoretical…

Astrophysics · Physics 2009-10-31 Marcelo B. Ribeiro

Creation of Cold Dark Matter (CCDM) can macroscopically be described by a negative pressure, and, therefore, the mechanism is capable to accelerate the Universe, without the need of an additional dark energy component. In this framework we…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 J. F. Jesus , F. A. Oliveira , S. Basilakos , J. A. S. Lima

Exact dynamical equations for a generic dust matter source field in a cosmological context are formulated with respect to a non-comoving Newtonian-like timelike reference congruence and investigated for internal consistency. On the basis of…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Henk van Elst , George F R Ellis

In relativistic inhomogeneous cosmology, structure formation couples to average cosmological expansion. A conservative approach to modelling this assumes an Einstein--de Sitter model (EdS) at early times and extrapolates this forward in…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Boudewijn F. Roukema , Pierre Mourier , Thomas Buchert , Jan J. Ostrowski

This is the second of two papers describing a model of galactic evolution in the submillimetre waveband. The model incorporates a self-consistent treatment of the evolution of dust and stars, is normalized to the submillimetre properties of…

Astrophysics · Physics 2015-06-24 Stephen Eales , Mike Edmunds

Inhomogeneous cosmological models have recently become a very interesting alternative to standard cosmology. This is because these models are able to fit cosmological observations without the need for dark energy. However, due to…

Astrophysics · Physics 2009-11-13 Krzysztof Bolejko , Paul Lasky

This article reviews an approach for constructing a simple relativistic fractal cosmology whose main aim is to model the observed inhomogeneities of the distribution of galaxies by means of the Lemaitre-Tolman solution of Einstein's field…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-27 Marcelo B. Ribeiro

The high precision attained by cosmological data in the last few years has increased the interest in exact solutions. Analytic expressions for solutions in the Standard Model are presented here for all combinations of $\Lambda = 0$,…

General Relativity and Quantum Cosmology · Physics 2009-09-29 R. Aldrovandi , R. R. Cuzinatto , L. G. Medeiros

Perhaps the deepest mystery of our accelerating Universe in expansion is the existence of a tiny and rigid cosmological constant, $\Lambda$. Its size is many orders of magnitude below the expected one in the standard model of particle…

General Relativity and Quantum Cosmology · Physics 2015-04-03 Joan Sola , Adria Gomez-Valent

The Lambda-Cold Dark Matter (LCDM) model agrees with most of the cosmological observations, but has some hindrances from observed data at smaller scales such as galaxies. Recently, Berezhiani and Khoury (2015) proposed a new theory…

General Relativity and Quantum Cosmology · Physics 2020-07-22 Shreya Banerjee , Sayantani Bera , David F. Mota

We study the nonlinear evolution of density perturbations in cosmologies where the late-time accelerated expansion is driven by a quintessence field with vanishing speed of sound. For these models matter and quintessence perturbations are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Guido D'Amico , Emiliano Sefusatti

We investigate the late time acceleration with a Chaplygin type of gas in spherically symmetric inhomogeneous model. At the early phase we get Einstien-deSitter type of solution generalised to inhomogeneous spacetime. But at late stage of…

General Relativity and Quantum Cosmology · Physics 2017-02-17 D. Panigrahi , S. Chatterjee
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