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Peculiar velocities thoughout the region of the local supercluster are reconstructed by two different orbit-retracing methods. The requirement of the optimal correlation between the radial components of reconstructed velocities and the…

Astrophysics · Physics 2009-11-13 Roya Mohayaee , R. Brent Tully

The velocity correlation functions directly measured from the peculiar velocity field of dark matter in numerical simulations are known to have an amplitude lower than that predicted by theoretical models at large scales. The trend persists…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-05 Yao-Tsung Chuang , Teppei Okumura , Takahiro Nishimichi

We give the first determination of the observed peculiar velocity distribution function for a representative sample of galaxies (within 50 Mpc (H=100) of the Local Group), which includes a wide range of clustering properties. We explore in…

Astrophysics · Physics 2009-10-28 Somak Raychaudhury , William C. Saslaw

The non-linear, scale-dependent bias in the mass distribution of galaxies and the underlying dark matter is a key systematic affecting the extraction of cosmological parameters from galaxy clustering. Using 95 million halos from the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Elise Jennings , Carlton M. Baugh , Dylan Hatt

Peculiar velocity surveys, which measure galaxy peculiar velocities directly from standard candles in addition to redshifts, can provide strong constraints on the linear growth rate of cosmological large-scale structure at low redshift. The…

We explore the potential of cross-correlating galaxies and peculiar velocities on non-linear scales to enhance cosmological constraints. Leveraging the \textsc{AbacusSummit} simulation suite and the halo occupation distribution (HOD)…

Galaxy peculiar velocities provide an integral source of cosmological information that can be harnessed to measure the growth rate of large scale structure and constrain possible extensions to General Relativity. In this work, we present a…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-30 Ryan J. Turner , Chris Blake , Rossana Ruggeri

The peculiar velocities of galaxies are an inherently valuable cosmological probe, providing an unbiased estimate of the distribution of matter on scales much larger than the depth of the survey. Much research interest has been motivated by…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Edward Macaulay , Hume A. Feldman , Pedro G. Ferreira , Andrew H. Jaffe , Shankar Agarwal , Michael J. Hudson , Richard Watkins

We describe a new method of overcoming problems inherent in peculiar velocity surveys by using data compression as a filter with which to separate large-scale, linear flows from small-scale noise that biases the results systematically. We…

Astrophysics · Physics 2007-05-23 Hume A Feldman , Richard Watkins , Adrian Melott , Will Chambers

The effects of sampling are investigated on measurements of counts-in-cells in three-dimensional magnitude limited galaxy surveys, with emphasis on moments of the underlying smooth galaxy density field convolved with a spherical window. A…

Astrophysics · Physics 2009-10-30 S. Colombi , I. Szapudi , A. S. Szalay

We measure the bulk flow of the local Universe using the 6dF Galaxy Survey peculiar velocity sample (6dFGSv), the largest and most homogeneous peculiar velocity sample to date. 6dFGSv is a Fundamental Plane sample of $\sim10^4$ peculiar…

We address the problem of discretizing continuous cosmological signals such as a galaxy distribution for further processing with Fast Fourier techniques. Discretizing, in particular representing continuous signals by discrete sets of sample…

Instrumentation and Methods for Astrophysics · Physics 2009-01-21 J. Jasche , F. S. Kitaura , T. A. Ensslin

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

We present and analyze an algorithm for estimating the size, under a Gaussian or uniform measure, of a localized neighborhood in neural network parameter space with behavior similar to an ``anchor'' point. We refer to this as the "local…

Machine Learning · Computer Science 2025-04-09 Adam Scherlis , Nora Belrose

Models of physics beyond the Standard Model often contain a large number of parameters. These form a high-dimensional space that is computationally intractable to fully explore. Experimental constraints project onto a subspace of viable…

High Energy Physics - Theory · Physics 2022-01-05 Jacob Hollingsworth , Michael Ratz , Philip Tanedo , Daniel Whiteson

Even though the computation of local properties, such as densities or radial distribution functions, remains one of the most standard goals of molecular simulation, it still largely relies on straighforward histogram-based strategies. Here…

Computational Physics · Physics 2020-10-28 Benjamin Rotenberg

One of the main problems of observational cosmology is to determine the range in which a reliable measurement of galaxy correlations is possible. This corresponds to determine the shape of the correlation function, its possible evolution…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Francesco Sylos Labini , Daniil Tekhanovich , Yurij V. Baryshev

We use numerical simulations to investigate the behaviour of the dipole moment of the spatial distribution of different kinds of mass tracers. We select density peaks of the simulated matter distribution with mean separations of 38 and 30…

Astrophysics · Physics 2015-06-24 V. Kolokotronis , M. Plionis , P. Coles , S. Borgani , L. Moscardini

In this work, we examine sampling problems with non-smooth potentials. We propose a novel Markov chain Monte Carlo algorithm for sampling from non-smooth potentials. We provide a non-asymptotical analysis of our algorithm and establish a…

Machine Learning · Computer Science 2022-02-11 Jiaming Liang , Yongxin Chen

We describe a new statistic for measuring the small-scale velocity dispersion of galaxies directly from redshift surveys. This statistic is based on the object-weighted statistic proposed by Davis, Miller, & White (1997). Compared with the…

Astrophysics · Physics 2007-05-23 Jonathan E. Baker , Marc Davis