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Related papers: Cosmography with $\Lambda$-Szekeres Models

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Cosmography is used in cosmological data processing in order to constrain the kinematics of the universe in a model-independent way. In this paper, we first investigate the effect of the ultraviolet (UV) and X-ray relation of a quasar on…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 J. P. Hu , F. Y. Wang

Cosmography is a powerful tool to investigate the Universe kinematic and then to reconstruct dynamics in a model-independent way. However, recent new measurements of supernovae Ia and quasars have populated the Hubble diagram up to high…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-19 Giada Bargiacchi , G. Risaliti , M. Benetti , S. Capozziello , E. Lusso , A. Saccardi , M. Signorini

The Szekeres inhomogeneous models can be used to model the true lumpy universe that we observe. This family of exact solutions to Einstein's equations was originally derived with a general metric that has no symmetries. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Anthony Nwankwo , Mustapha Ishak , John Thompson

The purpose of the present work is based on two main observations: the tensions encountered by the standard $\Lambda$CDM model when confronted to precision small scale cosmological data and the finding that the matter distribution and the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-20 Marie-Noëlle Célérier

Model-independent methods in cosmology has become an essential tool in order to deal with an increasing number of theoretical alternatives for explaining the late-time acceleration of the Universe. In principle, this provides a way of…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Vinicius C. Busti , Peter K. S. Dunsby , Alvaro de la Cruz-Dombriz , Diego Saez-Gomez

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform comparisons to the supernova Ia Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

We lay out a general framework for calculating the variation of a set of cosmological observables, down the past null cone of an arbitrarily placed observer, in a given arbitrary inhomogeneous metric. The observables include redshift,…

General Relativity and Quantum Cosmology · Physics 2018-02-21 Charles Hellaby , Anthony Walters

Cosmography, as an integral branch of cosmology, strives to characterize the Universe without relying on pre-determined cosmological models. This model-independent approach utilizes Taylor series expansions around the current epoch,…

General Physics · Physics 2024-06-11 Seokcheon Lee

Cosmological observables are used to construct cosmological models. Since cosmological observations are limited to the light cone, a fixed number of observables (even measured to arbitrary accuracy) may not uniquely determine a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-20 Edward W. Kolb , Callum R. Lamb

Using a new sub-sample of observed strong gravitational lens systems, for the first time, we present the equation for the angular diameter distance in the $y$-redshift scenario for cosmography and use it to test the cosmographic parameters.…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Andrés Lizardo , Mario H. Amante , Miguel A. García-Aspeitia , Juan Magaña , V. Motta

Context. Explaining the accelerated expansion of the Universe is one of the fundamental challenges in physics today. Cosmography provides information about the evolution of the universe derived from measured distances, assuming only that…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-05 Marek Demianski , Ester Piedipalumbo , Disha Sawant , Lorenzo Amati

Cosmography is an ideal tool to investigate the cosmic expansion history of the Universe in a model-independent way. The equations of motion in modified theories of gravity are usually very complicated; cosmography may select practical…

General Relativity and Quantum Cosmology · Physics 2021-01-04 Sanjay Mandal , Deng Wang , P. K. Sahoo

Cosmography is a useful tool to constrain cosmological models, in particular dark energy models. In the case of modified theories of gravity, where the equations of motion are generally quite complicated, cosmography can contribute to…

General Relativity and Quantum Cosmology · Physics 2010-12-23 Mariam Bouhmadi-Lopez , Salvatore Capozziello , Vincenzo F. Cardone

Cosmography represents an important branch of cosmology which aims to describe the universe without the need of postulating \emph{a priori} any particular cosmological model. All quantities of interest are expanded as a Taylor series around…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Peter K. S. Dunsby , Orlando Luongo

Real-time measurements are becoming feasible in cosmology, where the next generation of telescopes will detect the temporal change of redshifts and sky positions of individual sources with a precision that will allow a direct detection of…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Asta Heinesen , Mikołaj Korzyński

Cosmography is a phenomenological and relatively model-independent approach to cosmology, where physical quantities are expanded as a Taylor series in the cosmological redshift, or in related variables. Here we apply this methodology to…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-08 C. J. A. P. Martins , F. P. S. A. Ferreira , P. V. Marto

The light we observe from distant astrophysical objects including supernovae and quasars allows us to determine large distances in terms of a cosmological model. Despite the success of the standard cosmological model in fitting the data,…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-07 Angela L. H. Ng

In the present paper, we investigate the cosmographic problem using the bias-variance trade-off. We find that both the z-redshift and the $y=z/(1+z)$-redshift can present a small bias estimation. It means that the cosmography can describe…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-13 Ming-Jian Zhang , Hong Li , Jun-Qing Xia

The large scale structure of the universe is a complex web of clusters, filaments, and voids. Its properties are informed by galaxy redshift surveys and measurements of peculiar velocities. Wiener Filter reconstructions recover…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Helene M. Courtois , Daniel Pomarede , R. Brent Tully , Yehuda Hoffman , Denis Courtois

Cosmography can be considered as a sort of a model-independent approach to tackle the dark energy/modified gravity problem. In this review, the success and the shortcomings of the $\Lambda$CDM model, based on General Relativity and standard…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo
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