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Related papers: Probing Cosmology beyond $\Lambda$CDM using the SK…

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The standard model of cosmology is based on the hypothesis that the Universe is spatially homogeneous and isotropic. When interpreting most observations, this cosmological principle is applied stricto sensu: the light emitted by distant…

General Relativity and Quantum Cosmology · Physics 2024-01-15 Pierre Fleury

We examine the sky distribution of radio galaxies in the NRAO VLA Sky Survey (NVSS) and the Rapid ASKAP Continuum Survey (RACS). Analyses of these samples have reported tension between their inferred dipoles and the kinematic dipole of the…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-05 Oliver T. Oayda , Vasudev Mittal , Geraint F. Lewis , Tara Murphy

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 redshift of all cosmological sources drifts by a systematic velocity of order a few m/s over a century due to the deceleration of the Universe. The specific functional dependence of the predicted velocity shift on the source redshift…

Astrophysics · Physics 2011-02-11 Abraham Loeb

The new frontier of cosmology will be led by three-dimensional surveys of the large-scale structure of the Universe. Based on its all-sky surveys and redshift depth, the SKA is destined to revolutionize cosmology, in combination with future…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Roy Maartens , Filipe B. Abdalla , Matt Jarvis , Mario G. Santos

The cosmographic approach is adopted to determine the spatial curvature (i.e., $\Omega_K$) combining the latest released cosmic chronometers data (CC), the Pantheon sample of type Ia supernovae observations, and the baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 En-Kun Li , Minghui Du , Lixin Xu

The high-significance measurement of large-scale structure signals enables testing the isotropy of the Universe. The measurement of cosmological parameters through the large-scale distribution of matter is now a mature domain. This approach…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-01 G. Hurier

We are in motion against the cosmic backdrop. This motion is evidenced by the systematic temperature shift - or dipole anisotropy - observed in the Cosmic Microwave Background radiation (CMB). Because of the Doppler effect, the temperature…

Astrophysics · Physics 2015-06-24 Chris Blake , Jasper Wall

Cosmography is a model-independent phenomenological approach to observational cosmology, relying on Taylor series expansions of physical quantities as a function of the cosmological redshift or other analogous variables. A recent work…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-27 C. J. A. P. Martins

We analyze two volume limited galaxy samples from the SDSS photometric and spectroscopic data to test the isotropy in the local Universe. We use information entropy to quantify the global anisotropy in the galaxy distribution at different…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Suman Sarkar , Biswajit Pandey , Rishi Khatri

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

Cosmology and Nongalactic Astrophysics · Physics 2013-01-18 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

Physical constants and cosmological parameters could vary with position. On the largest scales such variations would manifest themselves as gradients across our Hubble volume, leading to dipole-modulation of the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-12 Adam Moss , Douglas Scott , James P. Zibin , Richard Battye

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

The rate at which the universe is expanding today is a fundamental parameter in cosmology which governs our understanding of structure formation and dark energy. However, current measurements of the Hubble constant, $H_0$, show a…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-02 Carlos A. P. Bengaly , Chris Clarkson , Roy Maartens

Scaling relations of galaxy clusters are a powerful probe of cosmic isotropy in the late Universe. Owing to their strong cosmological dependence, galaxy cluster scaling relations can obtain tight constraints on the spatial variation of…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-05 Konstantinos Migkas

The breakdown of statistical homogeneity and isotropy of cosmic perturbations is a generic feature of ultra large scale structure of the cosmos, in particular, of non trivial cosmic topology. The statistical isotropy (SI) of the Cosmic…

Astrophysics · Physics 2007-05-23 Amir Hajian , Tarun Souradeep

Recently collected SNIa data have been used to address the problem of measuring the cosmological parameters of the universe. Analysed in the framework of homogeneous models, they have yielded, as a primary result, a strictly positive…

Astrophysics · Physics 2007-05-23 Marie-Noëlle Célérier

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

In the past several decades, the standard cosmological model has been established and its parameters have been measured to a high precision, while there are still many of the fundamental questions in cosmology; such as the physics in the…

The standard cosmological model assumes the Cosmological Principle. However, recent observations hint at possible violations of isotropy on large scales, possibly through late-time anisotropic expansion. Here we investigate the potential of…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-12 James Adam , Roy Maartens , Julien Larena , Chris Clarkson , Ruth Durrer