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Related papers: Uneven flows: On cosmic bulk flows, local observer…

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We study the impact of systematic errors on planned weak lensing surveys and compute the requirements on their contributions so that they are not a dominant source of the cosmological parameter error budget. The generic types of error we…

Astrophysics · Physics 2010-04-06 Dragan Huterer , Masahiro Takada , Gary Bernstein , Bhuvnesh Jain

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

In order to deal with a large cosmological constant a relaxation mechanism based on modified gravity has been proposed recently. By virtue of this mechanism the effect of the vacuum energy density of a given quantum field/string theory (no…

General Relativity and Quantum Cosmology · Physics 2012-01-31 Spyros Basilakos , Florian Bauer , Joan Sola

We analyze the cosmic peculiar velocity field as traced by a sample of 1184 spiral, elliptical and S0 galaxies, grouped in 704 objects. We perform a statistical analysis, by calculating the bulk flow, Cosmic Mach Number and velocity…

Astrophysics · Physics 2009-10-22 Lauro Moscardini , Giuseppe Tormen , Sabino Matarrese , Francesco Lucchin

We present new measurements of the large-scale bulk flows of galaxy clusters based on 5-year WMAP data and a significantly expanded X-ray cluster catalogue. Our method probes the flow via measurements of the kinematic Sunyaev-Zeldovich (SZ)…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 A. Kashlinsky , F. Atrio-Barandela , H. Ebeling , A. Edge , D. Kocevski

We present a new numerical model to simulate settling trajectories of discretized individual or a mixture of particles of different geometrical shapes in a quiescent fluid and their flow trajectories in a flowing fluid. Simulations unveiled…

Computational Physics · Physics 2020-06-26 Hakan Başağaoğlu , Sauro Succi , Danielle Wyrick , Justin Blount

We present high signal-to-noise galaxy-galaxy lensing measurements of the BOSS CMASS sample using 250 square degrees of weak lensing data from CFHTLenS and CS82. We compare this signal with predictions from mock catalogs trained to match…

We study systematically which features in the cosmic microwave background (CMB) and large-scale structure (LSS) probe various inhomogeneous properties of the dark sectors (including neutrinos, dark matter, and dark energy). We stress, and…

Astrophysics · Physics 2007-07-11 Sergei Bashinsky

As one of Stage IV space-based telescopes, China Space Station Telescope (CSST) can perform photometric and spectroscopic surveys simultaneously to efficiently explore the Universe in extreme precision. In this work, we investigate several…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Haitao Miao , Yan Gong , Xuelei Chen , Zhiqi Huang , Xiao-Dong Li , Hu Zhan

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

Large-scale peculiar motions are believed to reflect the local inhomogeneity and anisotropy of the universe, triggered by the ongoing process of structure formation. As a result, realistic observers do not follow the smooth Hubble flow but…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Christos G. Tsagas , Miltiadis I. Kadiltzoglou

We present forecasts for constraints on cosmological models which can be obtained by forthcoming radio continuum surveys: the wide surveys with the LOw Frequency ARray (LOFAR), Australian Square Kilometre Array Pathfinder (ASKAP) and the…

In this study, we explore the characteristics of bulk flow across various redshift ranges within the frameworks of $f(R)$ gravity, perturbed $f(R)$ gravity, and perturbed $f(R)$ gravity coupled with neutrinos. Our investigation reveals…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-29 Muhammad Yarahmadi , Amin Salehi

A major aim of cosmological surveys is to test deviations from the standard $\Lambda$CDM model, but the full scientific value of these surveys will only be realised through efficient simulation methods that keep up with the increasing…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-06 Yash Gondhalekar , Sownak Bose , Baojiu Li , Carolina Cuesta-Lazaro

We present the second-order general relativistic description of the observed galaxy number density in a cosmological framework. The observed galaxy number density is affected by the volume and the source effects, both of which arise due to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Jaiyul Yoo , Matias Zaldarriaga

Gravitational lensing magnification alters the observed spatial distribution of galaxies and must be accounted for to prevent biases in cosmological probes of the large-scale structure. We investigate its effects on the Dark Energy Survey…

We examine the errors on counts in cells extracted from galaxy surveys. The measurement error, related to the finite number of sampling cells, is disentangled from the ``cosmic error'', due to the finiteness of the survey. Using the…

Astrophysics · Physics 2009-10-28 István Szapudi , Stéphane Colombi

The phenomenon of the very local ($\le3$ Mpc) Hubble flow is studied on the basis of the data of recent precision observations. A set of computer simulations is performed to trace the trajectories of the flow galaxies back in time to the…

We apply the method of matched asymptotic expansions to analyse whether cosmological variations in physical `constants' and scalar fields are detectable, locally, on the surface of local gravitationally bound systems such as planets and…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Douglas J. Shaw , John D. Barrow

Model-independent constraints on the spatial curvature are not only closely related to important problems such as the evolution of the Universe and properties of dark energy, but also provide a test of the validity of the fundamental…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Zhengxiang Li , Xuheng Ding , Guo-Jian Wang , Kai Liao , Zong-Hong Zhu
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