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Related papers: Simple inhomogeneous cosmological (toy) models

200 papers

We compare and combine likelihood functions of the cosmological parameters Omega_m, h and sigma_8 from the CMB, type Ia supernovae and from probes of large scale structure. We include the recent results from the CMB experiments BOOMERANG…

Astrophysics · Physics 2007-05-23 S. L. Bridle

We investigate observational constraints from lensing statistics and high-z type Ia supernovae on flat cosmological models with nonrelativistic matter and an exotic fluid with equation of state, $p_x=(m/3 -1)\rho_x$. We show that agreement…

Astrophysics · Physics 2008-11-26 Ioav Waga , Ana Paula M. R. Miceli

Exact luminosity distance and apparent magnitude formulas are applied to Union2 557 supernovae sample in order to constrain possible position of an observer outside of the center of symmetry in spherically symmetric inhomogeneous pressure…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Adam Balcerzak , Mariusz P. Dabrowski , Tomasz Denkiewicz

We study the performance of three pairs of tilted $\Lambda$CDM cosmological models, two pairs allowing for non-flat spatial hypersurfaces with CMB temperature and polarization power spectrum data (P18) from Planck, P18 lensing (lensing),…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Javier de Cruz Perez , Chan-Gyung Park , Bharat Ratra

We study the form of the luminosity distance as a function of redshift in the presence of large scale inhomogeneities, with sizes of order 10 Mpc or larger. We approximate the Universe through the Swiss-cheese model, with each spherical…

Astrophysics · Physics 2010-10-27 N. Brouzakis , N. Tetradis , E. Tzavara

Cosmological parameters are constrained by a wide variety of observations. We examine the concordance diagram for modern measurements of the Hubble constant, the shape parameter from large scale structure, the cluster baryon fraction, and…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-22 Stacy McGaugh

We present cosmological constraints for the flat $\Lambda$CDM model, including the sum of neutrino masses, by performing a multi-probe analysis of a total of 13 tomographic auto- and cross-angular power spectra. This is achieved by…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-11 Raphael Sgier , Christiane Lorenz , Alexandre Refregier , Janis Fluri , Dominik Zürcher , Federica Tarsitano

In a recent paper (Vigoureux et al. Int. J. Theor. Phys. 47:928, 2007) it has been suggested that the velocity of light and the expansion of the universe are two aspects of one single concept connecting space and time in the expanding…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-22 David Viennot , Jean-Marie Vigoureux

This paper concerns the so-called cosmological constant problem. In order to solve it, we propose a toy model providing an extension of the dimensionality of spacetime, with an additional spatial dimension which is macroscopically…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Wojciech P. Tarkowski

In the context of the Relativistic Quantum Geometry formalism, where the cosmological constant is promoted to a dynamical variable by attributing it a geometric interpretation as a result of a flux on the boundary of a manifold and…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Juan Ignacio Musmarra , Claudia Moreno , Rafael Hernández-Jiménez

There are investigated such cosmological models which instead of the usual spatial homogeneity property only fulfil the condition that in a certain synchronized system of reference all spacelike sections t = const. are homogeneous…

General Relativity and Quantum Cosmology · Physics 2008-11-26 H. -J. Schmidt

A plane-symmetric non-static cosmological model representing a bulk viscous fluid distribution has been obtained which is inhomogeneous and anisotropic and a particular case of which is gravitationally radiative. Without assuming any {\it…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Anirudh Pradhan , Hare Ram Pandey

We present a model-independent estimate of the angular homogeneity scale in the Local Universe by analysing data from the Southern Photometric Local Universe Survey (S-PLUS). Two complementary estimators are employed: (i) a parametric…

Homogeneous cosmological models with non-vanishing intrinsic curvature require a special treatment when they are quantized with loop quantum cosmological methods. Guidance from the full theory which is lost in this context can be replaced…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Ghanashyam Date , Kevin Vandersloot

Cosmographic approach, a Taylor expansion of the Hubble function, has been used as a model-independent method to investigate the evolution of the universe in the presence of cosmological data. Apart from possible technical problems like the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-04 Ahmad Mehrabi , Mehdi Rezaei

This paper is the third of a series dedicated to the study of the Delayed Big-Bang (DBB) class of inhomogeneous cosmological models of Lema\^itre-Tolman-Bondi type. In the first work, it was shown that the geometrical properties of the DBB…

General Relativity and Quantum Cosmology · Physics 2011-05-23 Marie-Noëlle Célérier

In the context of averaging an inhomogeneous cosmological model, we propose a natural measure identical to the Kullback-Leibler relative information entropy, which expresses the distinguishability of the local inhomogeneous density field…

General Relativity and Quantum Cosmology · Physics 2011-07-28 Masaaki Morita , Thomas Buchert , Akio Hosoya , Nan Li

Several models based on General Relativity and Modified Gravity aim to reproduce the observed universe with precision comparable to the flat-$\Lambda$CDM cosmological model. In this study, we investigate the consistency of some of these…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-05 Fernanda Oliveira , Bruno Ribeiro , Wiliam S. Hipólito-Ricaldi , Felipe Avila , Armando Bernui

Examples are presented of applications of the Lema\^{i}tre - Tolman model to problems of astrophysics and gravitation theory. They are: 1. Inferring the spatial distribution of matter by interpretation of observations; 2. Interaction of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Andrzej Krasiński

In this manuscript, we show that three fundamental building blocks are supporting the Cosmological Principle. The first of them states that there is a special frame in the universe where the spatial geometry is intrinsically homogeneous and…

General Relativity and Quantum Cosmology · Physics 2024-01-05 Leandro G. Gomes