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We study the cosmic velocity-density relation using the spherical collapse model (SCM) as a proxy to non-linear dynamics. Although the dependence of this relation on cosmological parameters is known to be weak, we retain the density…

Astrophysics · Physics 2013-11-22 Maciej Bilicki , Michał Chodorowski

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

We present an analysis of the ultraviolet (UV) continuum slopes ($\beta$) for a sample of $172$ galaxy candidates at $8 < z_{\mathrm{phot}} < 16$ selected from a combination of JWST NIRCam imaging and COSMOS/UltraVISTA ground-based…

We study the photometric properties and sizes of the reionization-epoch galaxies in high-resolution Simba cosmological hydrodynamical simulations with box sizes of $[25,50]~h^{-1}$Mpc. Assuming various attenuation laws, we compute…

Astrophysics of Galaxies · Physics 2020-04-29 Xiaohan Wu , Romeel Davé , Sandro Tacchella , Jennifer Lotz

Low redshift surveys of galaxy peculiar velocities provide a wealth of cosmological information. We revisit the idea of extracting this information by directly measuring the redshift-space momentum power spectrum from such surveys. We…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-19 Cullan Howlett

We study the rate of Bayesian consistency for hierarchical priors consisting of prior weights on a model index set and a prior on a density model for each choice of model index. Ghosal, Lember and Van der Vaart [2] have obtained general…

Statistics Theory · Mathematics 2008-09-23 Yang Xing

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 redshifts of lens galaxies in known gravitational lens systems probe the volume distribution of lensing mass. Following earlier work by Kochanek, we re-derive the lens redshift probability distribution, allowing for mass and number…

Astrophysics · Physics 2009-11-07 Eran O. Ofek , Hans-Walter Rix , Dan Maoz

The discrepancy between estimates of the Hubble Constant ($H_0$) measured from local ($z \lesssim 0.1$) scales and from scales of the sound horizon is a crucial problem in modern cosmology. Peculiar velocities ($v_{pec}$) of standard candle…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-18 Thomas M. Sedgwick , Chris A. Collins , Ivan K. Baldry , Philip A. James

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

In this work, by using strong gravitational lensing (SGL) observations along with Type Ia Supernovae (Union2.1) and gamma ray burst data (GRBs), we propose a new method to study a possible redshift evolution of $\gamma(z)$, the mass density…

General Relativity and Quantum Cosmology · Physics 2017-08-16 R. F. L. Holanda , S. H. Pereira , Deepak Jain

We present measurements of the cosmic shear correlation in the shapes of galaxies in the Suprime-Cam 2.1 deg^2 R_c-band imaging data. As an estimator of the shear correlation originated from the gravitational lensing, we adopt the aperture…

We present a concept study on weak lensing map reconstruction through the cosmic magnification effect in galaxy number density distribution. We propose a minimal variance linear estimator to minimize both the dominant systematical and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-16 Xinjuan Yang , Pengjie Zhang

We present a method for decomposing the cosmological velocity field in a given volume into its divergent component due to the density fluctuations inside the volume, and its tidal component due to the matter distribution outside the volume.…

Astrophysics · Physics 2007-05-23 Y. Hoffman , A. Eldar , S. Zaroubi , A. Dekel

The algorithm ZTRACE of Monaco & Efstathiou (1999) is applied to the IRAS PSCz catalogue to reconstruct the initial conditions of our local Universe with a resolution down to ~5 Mpc/h. The 1-point PDF of the reconstructed initial conditions…

We measure the distribution of velocity dispersions of groups of galaxies identified in the UZC catalog; we use the distribution to derive the group mass function. We introduce a new method which makes efficient use of the entire magnitude…

Astrophysics · Physics 2009-11-10 Armando Pisani , Massimo Ramella , Margaret J. Geller

The Wiener Filter (WF) technique enables the reconstruction of density and velocity fields from observed radial peculiar velocities. This paper aims at identifying the optimal design of peculiar velocity surveys within the WF framework. The…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Jenny G. Sorce , Yehuda Hoffman , Stefan Gottlöber

Reconstructing the mass density, velocity, and tidal (MTV) fields of dark matter from galaxy surveys is essential for advancing our understanding of the LSS of the Universe. In this work, we present a machine learning-based framework using…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-27 Feng Shi , Zitong Wang , Xiaohu Yang , Yizhou Gu , Chengliang Wei , Ming Li , Jiaxin Han , Zhejie Ding , Huiyuan Wang , Youcai Zhang , Wensheng Hong , Yirong Wang , Xiao-dong Li

We present precise constraints on the normalization of the power spectrum of mass fluctuations in the nearby universe, sigma_8, as a function of the mean local matter density, Omega_m. Using the observed local X-ray luminosity function of…

Astrophysics · Physics 2008-11-26 S. W. Allen , R. W. Schmidt , A. C. Fabian , H. Ebeling