English
Related papers

Related papers: Single Past Null Geodesic in the Lemaitre-Tolman-B…

200 papers

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

This paper studies the spatially homogeneous Einstein-de Sitter cosmological model in the context of a relativistic hierarchical (fractal) cosmology as developed in paper I (0807.0866). The Einstein-de Sitter model is treated as a special…

Astrophysics · Physics 2011-02-11 Marcelo B. Ribeiro

I discuss the spherically symmetric but inhomogeneous Lemaitre-Tolman- Bondi (LTB) metric, which provides an exact toy model for an inhomogeneous universe. Since we observe light rays from the past light cone, not the expansion of the…

Astrophysics · Physics 2008-11-26 Kari Enqvist

We derive a direct general map from the luminosity distance D(z) to the inhomogeneous matter distribution M(r) in the Lemaitre-Tolman-Bondi (LTB) cosmology and compute several examples. One of our examples explicitly demonstrates that it is…

Astrophysics · Physics 2008-12-18 Daniel J. H. Chung , Antonio Enea Romano

As an alternative to dark energy that explains the observed acceleration of the universe, it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB) solution of…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-04 Antonio Enea Romano , Misao Sasaki

As an alternative to dark energy it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB) solution of Einstein's field equations. In order to test this hypothesis…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Antonio Enea Romano

As an alternative to dark energy it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB) solution of Einstein's field equations. In order to test such an…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Antonio Enea Romano

We build a simple cosmological model by means of a parabolic Lema\^{i}tre-Tolman-Bondi (LTB) metric up to a redshift $z\simeq 0.4$, an hyperbolic Friedmann metric for $z\sim 0.4$ up to the scale where dimming galaxies are observed ($z\sim…

General Relativity and Quantum Cosmology · Physics 2009-07-06 Stefano Viaggiu

The possibility that we live in a special place in the universe, close to the centre of a large void, seems an appealing alternative to the prevailing interpretation of the acceleration of the universe in terms of a LCDM model with a…

Astrophysics · Physics 2009-06-23 Juan Garcia-Bellido , Troels Haugboelle

We present a new model universe based on the junction of FRW to flat Lemaitre-Tolman-Bondi (LTB) solutions of Einstein equations along our past light cone, bringing structures within the FRW models. The model is assumed globally to be…

Astrophysics · Physics 2008-11-26 Sh. Khosravi , E. Kourkchi , R. Mansouri , Y. Akrami

We construct the Lema\^itre-Tolman-Bondi (LTB) dust universe whose distance-redshift relation is equivalent to that in the concordance $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. In our model, the density distribution and…

Astrophysics · Physics 2009-08-18 Chul-Moon Yoo , Tomohiro Kai , Ken-ichi Nakao

Many recent researches have investigated the deviations from the Friedmannian cosmological model, as well as their consequences on unexplained cosmological phenomena, such as dark matter and the acceleration of the Universe. On the one…

General Relativity and Quantum Cosmology · Physics 2021-09-22 Sergio Cacciatori , Alessio Marrani , Federico Re

We study the solvability of a system of ordinary differential equations derived from null geodesics of the LTB metric with data given in terms of a so-called redshift parameter. Data is introduced along these geodesics by the luminosity…

Classical Analysis and ODEs · Mathematics 2011-11-23 Christopher Winfield

In this paper we attempt to answer to the question: can cosmic acceleration of the Universe have a fractal solution? We give an exact solution of a Lema\^itre-Tolman-Bondi (LTB) Universe based on the assumption that such a smooth metric is…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-30 Leonardo Cosmai , Giuseppe Fanizza , Francesco Sylos Labini , Luciano Pietronero , Luigi Tedesco

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

The inverse problem with Lema\^itre-Tolman-Bondi (LTB) universe models is discussed. The LTB solution for the Einstein equations describes the spherically symmetric dust-filled spacetime. The LTB solution has two physical functional degrees…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Chul-Moon Yoo

There has been much debate over whether or not one could explain the observed acceleration of the Universe with inhomogeneous cosmological models, such as the spherically-symmetric Lemaitre-Tolman-Bondi (LTB) models. It has been claimed…

Astrophysics · Physics 2009-11-11 R. Ali Vanderveld , Eanna E. Flanagan , Ira Wasserman

We revisited the problem of describing, on average, a fractal distribution of matter using a Lemaitre-Tolman-Bondi (LTB) solution. Here we study the fractal structure of our local universe having a fractal dimension and a scale transition,…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-05 Erick Pastén , Víctor H. Cárdenas

This paper presents numerical solutions of particular Lemaitre-Tolman models approximating a fractal behaviour along the past light cone, as discussed in paper I (0807.0866) of this series. The initial conditions of the numerical problem…

Astrophysics · Physics 2011-02-11 Marcelo B. Ribeiro

We consider the redshift drift and position drift associated with astrophysical sources in a formalism that is suitable for describing emitters and observers of light in an arbitrary spacetime geometry, while identifying emitters of a given…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-09 Sofie Marie Koksbang , Asta Heinesen
‹ Prev 1 2 3 10 Next ›