English
Related papers

Related papers: Kriging Interpolating Cosmic Velocity Field

200 papers

We report on advances to interpret current and future gravitational-wave events in light of astrophysical simulations. A machine-learning emulator is trained on numerical population-synthesis predictions and inserted into a Bayesian…

High Energy Astrophysical Phenomena · Physics 2019-10-30 Kaze W. K. Wong , Davide Gerosa

We assess the effect of the local large scale structure on the estimation of two-point statistics of the observed radial peculiar velocities of galaxies. A large N-body simulation is used to examine these statistics from the perspective of…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-01 Wojciech A. Hellwing , Adi Nusser , Martin Feix , Maciej Bilicki

We study the dependence of galaxy clustering on luminosity and stellar mass at redshifts z ~ [0.2-1] using the first zCOSMOS 10K sample. We measure the redshift-space correlation functions xi(rp,pi) and its projection wp(rp) for sub-samples…

A geometric numerical method for simulating suspensions of spherical and non-spherical particles with Stokes drag is proposed. The method combines divergence-free matrix-valued radial basis function interpolation of the fluid velocity field…

Computational Physics · Physics 2021-02-26 Benjamin K. Tapley , Helge I. Andersson , Elena Celledoni , Brynjulf Owren

A fundamental task in kernel methods is to pick nodes and weights, so as to approximate a given function from an RKHS by the weighted sum of kernel translates located at the nodes. This is the crux of kernel density estimation, kernel…

Machine Learning · Statistics 2020-02-25 Ayoub Belhadji , Rémi Bardenet , Pierre Chainais

Studies of disordered heterogeneous media and galaxy cosmology share a common goal: analyzing the distribution of particles at `microscales' to predict physical properties at `macroscales', whether for a liquid, composite material, or…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Oliver H. E. Philcox , Salvatore Torquato

We present two new dynamical tests of the biasing hypothesis. The first is based on the amplitude and the shape of the galaxy-galaxy correlation function, $\xi_g(r)$, where $r$ is the separation of the galaxy pair. The second test uses the…

Astrophysics · Physics 2015-06-24 Roman Juszkiewicz , Enrique Gaztanaga

The redshifts of ~250000 galaxies are used to study the Local Hole and its associated peculiar velocities. The sample, compiled from 6dFGS and SDSS provides wide sky coverage to a depth of ~300h-1Mpc. We have therefore examined K and r…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-07 J. R. Whitbourn , T. Shanks

We describe our nonlinear emulation (i.e., interpolation) framework that combines the halo occupation distribution (HOD) galaxy bias model with $N$-body simulations of nonlinear structure formation, designed to accurately predict the…

Starting from the observed distribution of galaxy clusters in redshift space we use a two--step procedure to recover their distances and peculiar velocities. After statistically correcting for the unobserved cluster distribution in the zone…

Astrophysics · Physics 2016-08-30 E. Branchini , M. Plionis

We present an analytic method for rapidly forecasting the accuracy of gravitational potential reconstruction possible from measurement of radial peculiar velocities of every galaxy cluster with M > M_th in solid angle \theta^2 and over…

Astrophysics · Physics 2009-11-07 Olivier Doré , Lloyd Knox , Alan Peel

We propose a method with better predictions at extreme values than the standard method of Kriging. We construct our predictor in two ways: by penalizing the mean squared error through conditional bias and by penalizing the conditional…

Methodology · Statistics 2018-08-28 Minyong R. Lee , Art B. Owen

The cosmological peculiar velocity field (deviations from the pure Hubble flow) of matter carries significant information on dark energy, dark matter and the underlying theory of gravity on large scales. Peculiar motions of galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-17 Adi Nusser , Enzo Branchini , Martin Feix

We present a new, simple, fast algorithm to numerically evolve disks of inelastically colliding particles surrounding a central star. Our algorithm adds negligible computational cost to the fastest existing collisionless N-body codes, and…

Astrophysics · Physics 2008-11-26 Yoram Lithwick , Eugene Chiang

The investigation of the statistical properties of maps of line centroids has been used for almost 50 years, but there is still no general agreement on their interpretation. We try to quantify which properties of underlying turbulent…

Astrophysics · Physics 2009-11-11 V. Ossenkopf , A. Esquivel , A. Lazarian , J. Stutzki

The theoretical basis of dark energy remains unknown and could signify a need to modify the laws of gravity on cosmological scales. In this study we investigate how the clustering and motions of galaxies can be used as probes of modified…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-10 Stuart Lyall , Chris Blake , Ryan Turner , Rossana Ruggeri , Hans Winther

We propose Multiscale Flow, a generative Normalizing Flow that creates samples and models the field-level likelihood of two-dimensional cosmological data such as weak lensing. Multiscale Flow uses hierarchical decomposition of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-16 Biwei Dai , Uros Seljak

A large bulk flow, which is in tension with the Lambda Cold Dark Matter ($\Lambda$CDM) cosmological model, has been observed. In this paper, we provide a physically plausible explanation of this bulk flow, based on the assumption that some…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-19 Yin-Zhe Ma , Christopher Gordon , Hume A. Feldman

We compute the bulk motions of cosmic voids, using a $\Lambda$CDM numerical simulation considering the mean velocities of the dark matter inside the void itself and that of the haloes in the surrounding shell. We find coincident values of…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-02 Diego G. Lambas , Marcelo Lares , Laura Ceccarelli , Andrés N. Ruiz , Dante J. Paz , Victoria E. Maldonado , Heliana E. Luparello

Much current interest in cosmology has revolved around the peculiar velocity field of galaxies. Many methods have been proposed to derive this, probably the most prominent being POTENT (Dekel et al. 1990). However, this is prone to many…

Astrophysics · Physics 2007-05-23 A. Newsam , J. F. L. Simmons , M. A. Hendry
‹ Prev 1 8 9 10 Next ›