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We use explainable neural networks to connect the evolutionary history of dark matter halos with their density profiles. The network captures independent factors of variation in the density profiles within a low-dimensional representation,…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-22 Luisa Lucie-Smith , Hiranya V. Peiris , Andrew Pontzen

A grand challenge of the 21st century cosmology is to accurately estimate the cosmological parameters of our Universe. A major approach to estimating the cosmological parameters is to use the large-scale matter distribution of the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Siamak Ravanbakhsh , Junier Oliva , Sebastien Fromenteau , Layne C. Price , Shirley Ho , Jeff Schneider , Barnabas Poczos

Establishing accurate morphological measurements of galaxies in a reasonable amount of time for future big-data surveys such as EUCLID, the Large Synoptic Survey Telescope or the Wide Field Infrared Survey Telescope is a challenge. Because…

Instrumentation and Methods for Astrophysics · Physics 2017-06-14 D. Tuccillo , M. Huertas-Company , E. Decenciere , S. Velasco-Forero

It is shown that the average magnitude - redshift diagram for a magnitude-limited sample of galaxies can be effectively used for mapping galaxy velocity field. This new approach is quantitatively introduced and applied to the CfA, ESO/LV…

Astrophysics · Physics 2016-06-08 Jacek Choloniewski

Generative deep learning methods built upon Convolutional Neural Networks (CNNs) provide a great tool for predicting non-linear structure in cosmology. In this work we predict high resolution dark matter halos from large scale, low…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-25 David Schaurecker , Yin Li , Jeremy Tinker , Shirley Ho , Alexandre Refregier

More precise measurements of galaxy clustering will be provided by the next generation of galaxy surveys such as DESI, WALLABY and SKA. To utilize this information to improve our understanding of the Universe, we need to accurately model…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-26 Fei Qin , David Parkinson , Adam R. H. Stevens , Cullan Howlett

We study the spatial distribution of dark matter halos in the Universe in terms of their number density contrast, related to the underlying dark matter fluctuation via a non-local and non-linear bias random field. The description of the…

Astrophysics · Physics 2009-10-30 Paolo Catelan , Sabino Matarrese , Cristiano Porciani

The large scale structure of the universe is a complex web of clusters, filaments, and voids. Its properties are informed by galaxy redshift surveys and measurements of peculiar velocities. Wiener Filter reconstructions recover…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Helene M. Courtois , Daniel Pomarede , R. Brent Tully , Yehuda Hoffman , Denis Courtois

We present a simple model for the shape of the distribution function of galaxy peculiar velocities. We show how both nonlinear and linear theory terms combine to produce a distribution which has an approximately Gaussian core with…

Astrophysics · Physics 2009-10-31 Ravi K. Sheth , Antonaldo Diaferio

In General Relativity, the average velocity field of dark matter around galaxy clusters is uniquely determined by the mass profile. The latter can be measured through weak lensing. We propose a new method of measuring the velocity field…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Tsz Yan Lam , Takahiro Nishimichi , Fabian Schmidt , Masahiro Takada

Joint analyses of the large-scale distribution of galaxies, and their motions under the gravitational influence of this density field, allow powerful tests of the cosmological model, including measurement of the growth rate of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-14 Chris Blake , Ryan J. Turner

We introduce a new technique based on artificial neural networks which allows us to make accurate predictions for the spectral energy distributions (SEDs) of large samples of galaxies, at wavelengths ranging from the far-ultra-violet to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. Almeida , C. M. Baugh , C. G. Lacey , C. S. Frenk , G. L. Granato , L. Silva , A. Bressan

We use the recently completed one billion particle Via Lactea II LambdaCDM simulation to investigate local properties like density, mean velocity, velocity dispersion, anisotropy, orientation and shape of the velocity dispersion ellipsoid,…

The Dark Matter (DM) distribution in dwarf galaxies provides crucial insights into both structure formation and the particle nature of DM. GraphNPE (Graph Neural Posterior Estimator), first introduced in Nguyen et al. (2023), is a novel…

Accurate modelling of redshift-space distortions (RSD) in galaxy clustering is essential for extracting cosmological information from current and forthcoming large-scale structure surveys. While perturbation theory is reliable on large…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-12 Cheng-Zong Ruan , Baojiu Li , Carlton M. Baugh , Sownak Bose , Alexander Eggemeier , David F. Mota

The number density of galaxy clusters across mass and redshift has been established as a powerful cosmological probe. Cosmological analyses with galaxy clusters traditionally employ scaling relations. However, many challenges arise from…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-08 M. Kosiba , N. Cerardi , M. Pierre , F. Lanusse , C. Garrel , N. Werner , M. Shalak

We study the distribution functions of mass and circular velocity for dark matter halos in N-body simulations of the $\Lambda$CDM cosmology, addressing redshift and environmental dependence. The dynamical range enables us to resolve…

We present velocity statistics of galaxies and their biases inferred from the statistics of the underlying dark matter using a cosmological hydrodynamic simulation of galaxy formation in low-density and spatially flat cold dark matter…

Astrophysics · Physics 2009-11-07 Kohji Yoshikawa , Y. P. Jing , Gerhard Börner

We show that current and imminent underground detectors are capable of precision astrometry of dark matter. First we show that galactic dark matter velocity distributions can be obtained from reconstructed tracks of dark matter scattering…

High Energy Physics - Phenomenology · Physics 2019-12-25 Joseph Bramante , Jason Kumar , Nirmal Raj

In this contribution we review the large body of work carried out over the past two decades to probe the dark matter in the local universe using redshift survey and peculiar velocity data. While redshift surveys have evolved rapidly over…

Astrophysics · Physics 2007-05-23 L. da Costa