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Related papers: Toward an Optimal Sampling of Peculiar Velocity Su…

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We present a refined deep-learning-based method to reconstruct the three-dimensional dark matter density, gravitational potential, and peculiar velocity fields in the Zone of Avoidance (ZOA), a region near the galactic plane with limited…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-07 Alexandra Dupuy , Donghui Jeong , Sungwook E. Hong , Ho Seong Hwang , Juhan Kim , Hélène M. Courtois

We present a new Unbiased Minimal Variance (UMV) estimator for the purpose of reconstructing the large--scale structure of the universe from noisy, sparse and incomplete data. Similar to the Wiener Filter (WF), the UMV estimator is derived…

Astrophysics · Physics 2009-10-31 Saleem Zaroubi

We present the reconstructed real-space density and the predicted velocity fields from the Two Mass Redshift Survey (2MRS). The 2MRS is the densest all-sky redshift survey to date and includes about 23,200 galaxies with extinction corrected…

Quantitative evaluations of differences and/or similarities between data samples define and shape optimisation problems associated with learning data distributions. Current methods to compare data often suffer from limitations in capturing…

Machine Learning · Computer Science 2024-01-23 Deborah Pelacani Cruz , George Strong , Oscar Bates , Carlos Cueto , Jiashun Yao , Lluis Guasch

We present a forward-modelled velocity field reconstruction algorithm that performs the reconstruction of the mass density field using only peculiar velocity data. Our method consistently accounts for the inhomogeneous Malmquist bias using…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-01 Supranta S. Boruah , Guilhem Lavaux , Michael J. Hudson

We present an improved POTENT method for reconstructing the velocity and mass density fields from radial peculiar velocities, test it with mock catalogs, and apply it to the Mark III Catalog. Method improvments: (a) inhomogeneous Malmquist…

Astrophysics · Physics 2009-10-31 A. Dekel , A. Eldar , T. Kolatt , A. Yahil , J. A. Willick , S. M. Faber , S. Courteau , D. Burstein

Weak lensing measurements are starting to provide statistical maps of the distribution of matter in the universe that are increasingly precise and complementary to cosmic microwave background maps. The probability distribution (PDF)…

Astrophysics · Physics 2009-11-10 Tong-Jie Zhang , Ue-Li Pen

We generate constrained realizations (CRs) of the density and peculiar velocity fields within $200 \; h^{-1} \, \mathrm{Mpc}$ from the final release of the Two-Micron All-Sky Redshift Survey (2MRS) $-$ the densest all-sky redshift survey to…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-29 Robert Lilow , Adi Nusser

Peculiar velocities, obtained from direct distance measurements, are data of choice to achieve constrained simulations of the Local Universe reliable down to a scale of a few Megaparsecs. Unlike redshift surveys, peculiar velocities are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jenny G. Sorce , Helene M. Courtois , Stefan Gottloeber , Yehuda Hoffman , R. Brent Tully

We present extensive tests of the Fast Action Method (FAM) for recovering the past orbits of mass tracers in an expanding universe from their redshift-space coordinates at the present epoch. The tests focus on the reconstruction of…

Astrophysics · Physics 2009-11-07 Enzo Branchini , Amiram Eldar , Adi Nusser

The Reverse Zeldovich Approximation (RZA) is a reconstruction method which allows to estimate the cosmic displacement field from galaxy peculiar velocity data and to constrain initial conditions for cosmological simulations of the Local…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Timur Doumler , Helene Courtois , Stefan Gottloeber , Yehuda Hoffman

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

The number density and correlation function of galaxies are two key quantities to characterize the distribution of the observed galaxy population. High-$z$ spectroscopic surveys, which usually involve complex target selection and are…

Astrophysics of Galaxies · Physics 2024-02-05 Jiacheng Meng , Cheng Li , Houjun Mo , Yangyao Chen , Kai Wang

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

We describe the construction of an N-body simulation that mimics the true velocity and mass-density fields in a box of side 256\hmpc about the Local Group , and the production of mock catalogs that mimic in detail current catalogs of…

Astrophysics · Physics 2009-10-28 Tsafrir Kolatt , Avishai Dekel , Galit Ganon , Jeffrey Willick

The reconstruction of the large scale velocity field from the grouped Cosmicflows-4 (CF4) database is presented. The lognormal bias of the inferred distances and velocities data is corrected by the Bias Gaussianization correction (BGc)…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-03 Yehuda Hoffman , Aurélien Valade , Noam I. Libeskind , Jenny G. Sorce , R. Brent Tully , Simon Pfeifer , Stefan Gottlöber , Daniel Pomaréde

The large scale structure of the universe is reconstructed by means of the Wiener filter and constrained realizations of Gaussian fields. The density field constructed from optically selected galaxies (Hudson \cite{Hudson}) has been sampled…

Astrophysics · Physics 2007-05-23 Y. Hoffman

Analyses of peculiar velocity surveys face several challenges, including low signal--to--noise in individual velocity measurements and the presence of small--scale, nonlinear flows. This is the second in a series of papers in which we…

Astrophysics · Physics 2009-11-07 Hume A. Feldman , Richard Watkins , Adrian L. Melott , Scott W. Chambers

We present an efficient implementation of Wiener filtering of real-space linear field and optimal quadratic estimator of its power spectrum Band-powers. We first recast the field reconstruction into an optimization problem, which we solve…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-16 Benjamin Horowitz , Uros Seljak , Grigor Aslanyan

Reconstructing the density fluctuations in the early Universe that evolved into the distribution of galaxies we see today is a challenge of modern cosmology [ref.]. An accurate reconstruction would allow us to test cosmological models by…

Astrophysics · Physics 2015-06-24 Uriel Frisch , Sabino Matarrese , Roya Mohayaee , Andrei Sobolevski