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The standard method of measuring the galaxy pairwise velocity dispersion on small scales is heavily weighted by the densest regions in a way that is difficult to calibrate. We propose a new statistic which measures the small-scale velocity…

Astrophysics · Physics 2009-10-30 Michael A. Strauss , Jeremiah P. Ostriker , Renyue Cen

Galaxy peculiar velocities are excellent cosmological probes provided that biases inherent to their measurements are contained before any study. This paper proposes a new algorithm based on an object point process model whose probability…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-01 Jenny G. Sorce , Radu S. Stoica , Elmo Tempel

Measurements of the peculiar velocities of large samples of galaxies enable new tests of the standard cosmological model, including determination of the growth rate of cosmic structure that encodes gravitational physics. With the size of…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-19 Chris Blake , Ryan J. Turner

The local galaxy peculiar velocity field can be reconstructed from the surrounding distribution of large-scale structure and plays an important role in calibrating cosmic growth and expansion measurements. In this paper, we investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 Ryan J. Turner , Chris Blake

We consider a generalization of the discrete-time Self Healing Umbrella Sampling method, which is an adaptive importance technique useful to sample multimodal target distributions. The importance function is based on the weights (namely the…

Probability · Mathematics 2017-09-04 Gersende Fort , Benjamin Jourdain , Tony Lelièvre , Gabriel Stoltz

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

The statistics of peaks in weak gravitational lensing maps is a promising technique to constrain cosmological parameters in present and future surveys. Here we investigate its power when using general extreme value statistics which is very…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-12 Robert Reischke , Matteo Maturi , Matthias Bartelmann

We present an empirical method for estimating the underlying redshift distribution N(z) of galaxy photometric samples from photometric observables. The method does not rely on photometric redshift (photo-z) estimates for individual…

Astrophysics · Physics 2008-11-26 Marcos Lima , Carlos E. Cunha , Hiroaki Oyaizu , Joshua Frieman , Huan Lin , Erin S. Sheldon

In this paper, we develop the method of analyzing the velocity field of cosmic matter with a multiresolution decomposition. This is necessary in calculating the redshift distortion of power spectrum in the discrete wavelet transform (DWT)…

Astrophysics · Physics 2009-11-06 Xiao-Hu Yang , Long-Long Feng , Yao-Quan Chu , Li-Zhi Fang

We analyse and improve the volume-penalty method, a simple and versatile way to model objects in fluid flows. The volume-penalty method is a kind of fictitious-domain method that approximates no-slip boundary conditions with rapid linear…

Numerical Analysis · Mathematics 2020-12-09 Eric W. Hester , Geoffrey M. Vasil , Keaton J. Burns

The power spectrum (PS) of mass density fluctuations, in the range $0.05 \leq k \leq 0.2 \ihmpc$, is derived from the Mark III catalog of peculiar velocities of galaxies, independent of ``biasing". It is computed from the density field as…

Astrophysics · Physics 2016-08-30 Tsafrir Kolatt , Avishai Dekel

Future microwave sky surveys will have the sensitivity to detect the kinematic Sunyaev-Zeldovich signal from moving galaxy clusters, thus providing a direct measurement of their line-of-sight peculiar velocity. We show that cluster peculiar…

Astrophysics · Physics 2009-11-11 Suman Bhattacharya , Arthur Kosowsky

Since the volume accessible to galaxy surveys is fundamentally limited, it is extremely important to analyse available data in the most optimal fashion. One way of enhancing the cosmological information extracted from the clustering of…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-20 David W. Pearson , Lado Samushia , Praful Gagrani

State-space models have been used in many applications, including econometrics, engineering, medical research, etc. The maximum likelihood estimation (MLE) of the static parameter of general state-space models is not straightforward because…

Methodology · Statistics 2025-02-04 Yuxiong Gao , Wentao Li , Rong Chen

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

Galaxy distances and derived radial peculiar velocity catalogs constitute valuable datasets to study the dynamics of the Local Universe. However, such catalogs suffer from biases whose effects increase with the distance. Malmquist biases…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Jenny G. Sorce

The velocity dispersion of galaxies on small scales ($r\sim1h^{-1}$ Mpc), $\sigma_{12}(r)$, can be estimated from the anisotropy of the galaxy-galaxy correlation function in redshift space. We apply this technique to ``mock-catalogs''…

Astrophysics · Physics 2009-10-28 Rachel S. Somerville , Joel R. Primack , Richard Nolthenius

Probability density function estimation with weighted samples is the main foundation of all adaptive importance sampling algorithms. Classically, a target distribution is approximated either by a non-parametric model or within a parametric…

Machine Learning · Computer Science 2023-10-16 Julien Demange-Chryst , François Bachoc , Jérôme Morio , Timothé Krauth

We derive the sampling probability density function (pdf) of an ideal localized random electromagnetic field, its amplitude and intensity in an electromagnetic environment that is quasi-statically time-varying statistically homogeneous or…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 L. R. Arnaut

Sampling from distributions of implicitly defined shapes enables analysis of various energy functionals used for image segmentation. Recent work describes a computationally efficient Metropolis-Hastings method for accomplishing this task.…

Computer Vision and Pattern Recognition · Computer Science 2012-05-17 Jason Chang , John W. Fisher