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Related papers: Cosmology with Peculiar Velocities: Observational …

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Peculiar velocity surveys have non-uniform spatial distributions of tracers, so that the bulk flow estimated from them does not correspond to that of a simple volume such as a sphere. Thus bulk flow estimates are generally not strictly…

Astrophysics · Physics 2010-11-24 Richard Watkins , Hume A. Feldman , Michael J. Hudson

The line-of-sight peculiar velocities are good indicators of the gravitational fluctuation of the density field. Techniques have been developed to extract cosmological information from the peculiar velocities in order to test the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 Fei Qin

Recent surveys seem to support bulk peculiar velocities well in excess of those anticipated by the standard cosmological model. In view of these results, we consider here some of the theoretical implications of large-scale drift motions. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Christos G Tsagas

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

Cosmological parameters can be measured by comparing peculiar velocities with those predicted from a galaxy density field. Previous work has tested the accuracy of this approach with N-body simulations, but generally on idealised mock…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-27 Amber M. Hollinger , Michael J. Hudson

Bulk flow velocities are typically estimated in the idealised picture where observers are moving within a perfectly homogeneous and isotropic space-time. This picture is consistent within standard perturbation theory up to relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-22 Asta Heinesen

Maximum Likelihood estimation of the bulk flow from radial peculiar motions of galaxies, generally assumes a constant velocity field inside the survey volume. The assumption is inconsistent with the definition of the bulk flow as the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Adi Nusser

Peculiar velocities are the motions of galaxies due to the gravitational influence of large-scale structure, and thus are an important cosmological probe of the underlying matter density field. In recent years the number of surveys designed…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-19 Ryan J. Turner

We compare the bulk flow of the SMAC sample to the predictions of popular cosmological models and to other recent large-scale peculiar velocity surveys. Both analyses account for aliasing of small-scale power due to the sparse and…

We present a simple method for measuring cosmological bulk flows from large redshift surveys, based on the apparent dimming or brightening of galaxies due to their peculiar motion. It is aimed at estimating bulk flows of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Adi Nusser , Enzo Branchini , Marc Davis

We review the use of peculiar velocities of galaxies as a probe of cosmological models. We put particular emphasis on comparison of the peculiar velocity and density fields, focussing on the discrepancies between various recent analyses. We…

Astrophysics · Physics 2007-05-23 Michael A. Strauss , Michael Blanton

We present an improved Minimal Variance (MV) method for using a radial peculiar velocity sample to estimate the average of the three-dimensional velocity field over a spherical volume, which leads to an easily interpretable bulk flow…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-29 Sarah Peery , Richard Watkins , Hume A. Feldman

Using N-body simulations we study the impact of various systematic effects on the bulk flow (BF) and the Cosmic Mach Number (CMN). We consider two types of systematics: those related to survey properties and those induced by observer's…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Wojciech A. Hellwing , Maciej Bilicki , Noam I. Libeskind

Bulk peculiar flows are commonplace in the universe, with many surveys reporting their presence on scales spanning between few hundred and several hundred Mpc. However, the sizes and the speeds of some of these bulk flows are well in excess…

General Relativity and Quantum Cosmology · Physics 2025-11-26 Christos G. Tsagas

I review the recent developments in the analysis of cosmic flow data, in particular, latest results of bulk flow measurements, comparison between redshift and peculiar velocity catalogs with emphasis on the measured value of the $\beta…

Astrophysics · Physics 2007-05-23 Saleem Zaroubi

The existence of 'peculiar' velocities due to the formation of cosmic structure marks a point of discord between the real Universe and the usually assumed Friedmann-Lema\'{i}tre-Robertson-Walker metric which accomodates only the smooth…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-09 Roya Mohayaee , Mohamed Rameez , Subir Sarkar

Although bulk peculiar motions are commonplace in the universe, most theoretical studies either bypass them, or take the viewpoint of the idealised Hubble-flow observers. As a result, the role of these peculiar flows remains largely…

General Relativity and Quantum Cosmology · Physics 2021-09-24 C. G. Tsagas , M. I. Kadiltzoglou , K. Asvesta

Peculiar velocities of clusters of galaxies can be measured by studying the fluctuations in the cosmic microwave background (CMB) generated by the scattering of the microwave photons by the hot X-ray emitting gas inside clusters. While for…

Astrophysics · Physics 2010-11-26 A. Kashlinsky , F. Atrio-Barandela , D. Kocevski , H. Ebeling

It has been argued recently that the galaxy peculiar velocity field provides evidence of excessive power on scales of $50\hmpc$, which seems to be inconsistent with the standard $\Lambda$CDM cosmological model. We discuss several…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Yin-Zhe Ma , Douglas Scott

In this chapter we review observations and techniques for measuring both bulk flows in prominences and prominence mass. Measuring these quantities is essential to development and testing of models discussed throughout this book. Prominence…

Solar and Stellar Astrophysics · Physics 2015-02-04 T. A. Kucera
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