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Related papers: Analyzing the Large-Scale Bulk Flow using CosmicFl…

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We present a novel extended version of the $\Lambda$CDM model that provides analytical solution for Hubble parameter uniting all epochs of cosmic evolution starting from inflation to late-acceleration, with intermediate radiation and…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-31 Vishnu A Pai , Titus K Mathew

A formalism is presented that allows cosmological experiments to be tested for consistency, and allows a simple frequentist interpretation of the resulting significance levels. As an example of an application, this formalism is used to…

Astrophysics · Physics 2009-10-07 Max Tegmark , Emory Bunn , Wayne Hu

The trajectories since z=4 of systems of galaxies (`halos') with cz < 8,000 km/s are found through Numerical Action reconstructions. A set of 9,719 halos from a 2MASS group catalog and Cosmicflows-3 catalogs are given attention. Present…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-30 Edward Shaya , R. Brent Tully , Daniel Pomarède , Alan Peel

The peculiar motions of galaxies can be used to infer the distribution of matter in the Universe. It has recently been shown that measurements of the peculiar velocity field indicates an anomalously high bulk flow of galaxies in our local…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Edward Macaulay , Hume A. Feldman , Pedro G. Ferreira , Michael J. Hudson , Richard Watkins

Observations have repeatedly confirmed the presence of large-scale peculiar motions in the universe, commonly referred to as ``bulk flows''. These are vast regions of the observable universe, typically spanning scales of several hundred…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-06 Christos G. Tsagas , Leandros Perivolaropoulos , Kerkyra Asvesta

We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 < D_LG < 3.0 Mpc, the Local flow…

Astrophysics · Physics 2009-11-13 I. D. Karachentsev , O. G. Kashibadze , D. I. Makarov , R. B. Tully

We estimate the power spectrum of mass density fluctuations from peculiar velocities of galaxies by applying an improved maximum-likelihood technique to the new all-sky SFI catalog. Parametric models are used for the power spectrum and the…

An intriguing discrepancy emerging in the concordance model of cosmology is the tension between the locally measured value of the Hubble rate, and the 'global' value inferred from the cosmic microwave background (CMB). This could be due to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Vinicius C. Busti , Chris Clarkson , Marina Seikel

It has been observed that the locally measured Hubble parameter converges quickest to the background value and the dipole structure of the velocity field is smallest in the reference frame of the Local Group of galaxies. We study the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-11 David Kraljic , Subir Sarkar

We present the first cosmological constraints derived from the analysis of the void size function. This work relies on the final BOSS DR12 data set, a large spectroscopic galaxy catalog, ideal for the identification of cosmic voids. We…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 Sofia Contarini , Alice Pisani , Nico Hamaus , Federico Marulli , Lauro Moscardini , Marco Baldi

In this article, we investigate the mechanism of cosmological expansion and inflation by modeling dark energy as a four-dimensional continuous medium, with its elastic deformation described by a four-dimensional vector field. We demonstrate…

General Physics · Physics 2024-06-07 Mathieu R. Beau

Claims of local ($z \lesssim 0.05$) anisotropy in the Hubble constant have been made based on direct distance tracers such as Tully-Fisher galaxies and Type Ia supernovae. We revisit these using the CosmicFlows-4 Tully-Fisher W1 subsample,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-28 Richard Stiskalek , Harry Desmond , Guilhem Lavaux

We model the kinematics of the high- and intermediate- velocity clouds (HVCs and IVCs) observed in absorption towards a sample of 55 Galactic halo stars with accurate distance measurements. We employ a simple model of a thick disc whose…

Astrophysics of Galaxies · Physics 2022-05-25 A. Marasco , F. Fraternali , N. Lehner , J. C. Howk

The Hubble constant ($H_0$) is one of the most important parameters in the standard $\rm \Lambda CDM$ model. The measurements given by the main two methods show a gap larger than $4\sigma$, which is known as Hubble tension. Fast radio…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-18 D. H. Gao , Q. Wu , J. P. Hu , S. X. Yi , X. Zhou , F. Y. Wang , Z. G. Dai

We propose a dynamical dark energy model based on a canonical scalar field with a hybrid potential of the form $V(\phi) = V_{0}e^{-\lambda\phi} + V_{1}\phi^{n}$. We constrain the model's 11-dimensional parameter space using a comprehensive…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-30 Arpit Kottur , Jui Mahajan , Raka Dabhade

We present a detailed analysis (including redshift tomography) of the cosmic dipoles in the Keck+VLT quasar absorber and in the Union2 SnIa samples. We show that the fine structure constant cosmic dipole obtained through the Keck+VLT quasar…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Antonio Mariano , Leandros Perivolaropoulos

We demonstrate the capabilities of probabilistic diffusion models to reduce dramatically the computational cost of expensive hydrodynamical simulations to study the relationship between observable baryonic cosmological probes and dark…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Satvik Mishra , Roberto Trotta , Matteo Viel

The assumption of isotropy -- that the Universe looks the same in all directions on large scales -- is fundamental to the standard cosmological model. This model forms the building blocks of essentially all of our cosmological knowledge to…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-29 Jessica A. Cowell , Suhail Dhawan , Hayley J. Macpherson

We present an analysis comparing the bulk--flow measurements for six recent peculiar velocity surveys, namely, ENEAR, SFI, RFGC, SBF and the Mark III singles and group catalogs. We study whether the direction of the bulk--flow estimates are…

Astrophysics · Physics 2009-03-19 Devdeep Sarkar , Hume A. Feldman , Richard Watkins

We consider large-scale collective motion of flat edge-on spiral galaxies from the Revised Flat Galaxy Catalogue (RFGC) taking into account the curvature of space-time in the Local Universe at the scale 100 Mpc/h. We analyse how the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Serge Parnovsky , Aleksei Parnowski
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