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Related papers: New constraints on cosmic anisotropy from galaxy c…

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Studies of cluster mass and velocity anisotropy profiles are useful tests of dark matter models, and of the assembly history of clusters of galaxies. These studies might be affected by unknown systematics caused by projection effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-18 Tania Aguirre Tagliaferro , Andrea Biviano , Gabriella De Lucia , Emiliano Munari , Diego Garcia Lambas

In this paper, we investigate the possible deviations of the cosmic distance duality relation (CDDR) using the combination of the largest SNe Ia (Pantheon) and compact radio quasar (QSO) samples through two model-independent approaches. The…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-27 Yuan He , Yu Pan , Dong-Ping Shi , Shuo Cao , Wen-Jie Yu , Jing-Wang Diao , Wei-Liang Qian

Galaxy clusters are the most recent products of hierarchical accretion over cosmological scales. The gas accreted from the cosmic field is thermalized inside the cluster halo. Gas entropy and pressure are expected to have a self-similar…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-23 V. Ghirardini , S. Ettori , S. Amodeo , R. Capasso , M. Sereno

(abridged) We use a theoretical model to predict the clustering properties of galaxy clusters. Our technique accounts for past light-cone effects on the observed clustering and follows the non-linear evolution of the dark matter correlation…

Astrophysics · Physics 2009-10-31 Lauro Moscardini , Sabino Matarrese , H. J. Mo

We study the large-scale anisotropy of the Universe by measuring the dipole in the angular distribution of a flux-limited, all-sky sample of 1.36 million quasars observed by the Wide-field Infrared Survey Explorer (WISE). This sample is…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-01 Nathan Secrest , Sebastian von Hausegger , Mohamed Rameez , Roya Mohayaee , Subir Sarkar , Jacques Colin

We investigate the effects of stochasticity in the spatial and temporal distribution of supernova remnants on the anisotropy of cosmic rays observed at Earth. The calculations are carried out for different choices of the diffusion…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Pasquale Blasi , Elena Amato

We introduce the $dipole$ $cosmological$ $principle$, the idea that the Universe is a maximally Copernican cosmology, compatible with a cosmic flow. It serves as the most symmetric paradigm that generalizes the FLRW ansatz, in light of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-17 Chethan Krishnan , Ranjini Mondol , M. M. Sheikh-Jabbari

Using a three-component, multi-scale diffusion model, we show that the cosmic-ray (CR) proton and helium spectra and the dipole anisotropy can be explained with reasonable parameters. The model includes a nearby source associated with the…

High Energy Astrophysical Phenomena · Physics 2022-03-02 Yiran Zhang , Siming Liu , Houdun Zeng

Context. Gravitational collapse theory and numerical simulations suggest that the velocity field within large-scale galaxy filaments is dominated by motions along the filaments. Aims. Our aim is to check whether observational data reveal…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-25 Elmo Tempel , Antti Tamm

The cosmological principle asserts that on sufficiently large scales the Universe is homogeneous and isotropic on spatial slices. To deviate from this principle requires a departure from the FLRW ansatz. In this paper we analyze the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-23 Andrei Constantin , Thomas R. Harvey , Sebastian von Hausegger , Andre Lukas

Inflation predicts that the Universe is spatially flat. The Planck 2018 measurements of the cosmic microwave background anisotropy favour a spatially closed universe at more than 2$\sigma$ confidence level. We use model independent methods…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-07 Yingjie Yang , Yungui Gong

The observed two-point correlation functions of galaxies in redshift space become anisotropic due to the geometry of the universe as well as due to the presence of the peculiar velocity field. On the basis of linear perturbation theory, we…

Astrophysics · Physics 2009-10-30 Takahiro T. Nakamura , Takahiko Matsubara , Yasushi Suto

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 investigate the cosmological implications of studying galaxy clustering using a tomographic approach applied to the final BOSS DR12 galaxy sample, including both auto- and cross-correlation functions between redshift shells. We model the…

The Cosmological Principle states that the Universe is statistically isotropic and homogeneous on large scales. In particular, this implies statistical isotropy in the galaxy distribution, after removal of a dipole anisotropy due to the…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-16 Carlos A. P. Bengaly , Roy Maartens , Nandrianina Randriamiarinarivo , Albert Baloyi

To fully extract cosmological information from nonlinear galaxy distribution in redshift space, it is essential to include higher-order statistics beyond the two-point correlation function. In this paper, we propose a new decomposition…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-20 Naonori S. Sugiyama , Shun Saito , Florian Beutler , Hee-Jong Seo

Cosmological distances as a function of redshift depend on the effective curvature density via the effect on the geometrical path of photons from large scale spatial curvature and its effect on the expansion history, H(z). Cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-23 Edvard Mortsell , Jakob Jonsson

We discuss how Type Ia supernovae (SNe) strongly magnified by foreground galaxy clusters should be self-consistently treated when used in samples fitted for the cosmological parameters. While the cluster lens magnification of a SN can be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Adi Zitrin , Matthias Redlich , Tom Broadhurst

A recent study of the rotation of the plane of polarization of light from 160 cosmological sources claims to find significant evidence for cosmological anisotropy. We point out methodological weaknesses of that study, and reanalyze the same…

Astrophysics · Physics 2009-12-30 Thomas J. Loredo , Eanna E. Flanagan , Ira M. Wasserman

In the standard diffusive picture for transport of cosmic rays (CRs), a gradient in the CR density induces a typically small, dipolar anisotropy in their arrival directions. This has been widely advertised as a tool for finding nearby…

High Energy Astrophysical Phenomena · Physics 2015-01-15 Philipp Mertsch , Stefan Funk