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Related papers: Distances and lensing in cosmological void models

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We use supernovae measurements, calibrated by the local determination of the Hubble constant $H_0$ by SH0ES, to interpolate the distance-redshift relation using Gaussian process regression. We then predict, independent of the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-08 Shivam Pandey , Marco Raveri , Bhuvnesh Jain

The number of galaxies with measured redshifts > 1 is at present rapidly increasing, allowing for measurements of their correlation function. The correlations function is measured in redshift space, as a function of angular separation and…

Astrophysics · Physics 2009-10-31 Vibhat Nair

We review various cosmological models with a local underdense region (local void) and the averaged models with the backreaction of inhomogeneities, which have been proposed to explain (without assuming a positive cosmological constant) the…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-09 Kenji Tomita

We investigate the distance-redshift relation in the simple void model. As discussed by Moffat and Tatarski, if the observer stays at the center of the void, the observed Hubble parameter is not so different from the background Hubble…

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 present a fully relativistic framework to evaluate the impact of stochastic inhomogeneities on the prediction of the Hubble-Lema\^itre diagram. In this regard, we relate the fluctuations of the luminosity distance-redshift relation in…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-27 Giuseppe Fanizza

The increasing precision in the determination of the Hubble parameter has reached a per cent level at which large-scale cosmic flows induced by inhomogeneities of the matter distribution become non-negligible. Here we use large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Radoslaw Wojtak , Alexander Knebe , William A. Watson , Ilian T. Iliev , Steffen Hess , David Rapetti , Gustavo Yepes , Stefan Gottloeber

We have previously shown that spherically symmetric, inhomogeneous universe models can explain both the supernova data and the location of the first peak in the CMB spectrum without resorting to dark energy. In this work, we investigate…

Astrophysics · Physics 2008-11-26 Havard Alnes , Morad Amarzguioui

For known gravitational lens systems the redshift distribution of the lenses is compared with theoretical expectations for $10^{4}$~Friedmann-Lema\^\i tre~cosmological models, which more than cover the range of possible cases. The…

Astrophysics · Physics 2011-05-23 Phillip Helbig , Rainer Kayser

Most of current cosmological theories are built combining an isotropic and homogeneous manifold with a scale factor that depends on time. If one supposes a hyperconical universe with linear expansion, an inhomogeneous metric can be obtained…

General Relativity and Quantum Cosmology · Physics 2018-10-02 Robert Monjo

Most cosmological data analysis today relies on the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, providing the basis of the current standard cosmological model. Within this framework, interesting tensions between our increasingly…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-01 Hayley J. Macpherson , Asta Heinesen

The interpretation of cosmological observations relies on a notion of an average Universe, which is usually considered as the homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker (FLRW) model. However, inhomogeneities may…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-24 Michel-Andrès Breton , Pierre Fleury

The presence of inhomogeneities modifies the cosmic distances through the gravitational lensing effect, and, indirectly, must affect the main cosmological tests. Assuming that the dark energy is a smooth component, the simplest way to…

Astrophysics · Physics 2008-11-26 R. C. Santos , J. V. Cunha , J. A. S. Lima

The standard analysis of the CMB data assumes that the distance to the last scattering surface can be calculated using the distance-redshift relation as in the Friedmann model. However, in the inhomogeneous universe, even if <\delta\rho>…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Krzysztof Bolejko

We consider the effect on the propagation of light of inhomogeneities with sizes of order 10 Mpc or larger. The Universe is approximated through a variation of the Swiss-cheese model. The spherical inhomogeneities are void-like, with…

Astrophysics · Physics 2010-02-17 Nikolaos Brouzakis , Nikolaos Tetradis , Eleftheria Tzavara

Usually, we assume that there is no inhomogeneity isotropic in terms of our location in our uni- verse. This assumption has not been observationally confirmed yet in sufficient accuracy, and we need to consider the possibility that there…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-06 Hiroyuki Negishi , Ken-ichi Nakao

I investigate through simulations the redshift dependence of several lensing measures for two cosmological models, a flat universe with a cosmological constant (\LambdaCDM), and an open universe (OCDM). I argue that quintessence models can…

Astrophysics · Physics 2007-05-23 Antonio C. C. Guimarães

The data of type Ia supernovae observed by the High-z SN Search Team and Supernova Cosmology Project are analyzed in inhomogeneous cosmological models with a local void on scales of about 200 Mpc, to derive the best-fit values of model…

Astrophysics · Physics 2009-11-06 Kenji Tomita

Strong gravitational lensing of sources with different redshifts has been used to determine cosmological distance ratios, which in turn depend on the expansion history. Hence, such systems are viewed as potential tools for constraining…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Peter Schneider

Standard cosmology is constructed upon the (generally implicit) assumption of the ``large scale'' homogeneity of our Universe. Now, structures are observed at scales which become larger and larger as the observational distances increase.…

Astrophysics · Physics 2007-05-23 Marie-Noelle Celerier