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相关论文: Forecasting the accuracy of velocity-field reconst…

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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…

宇宙学与河外天体物理 · 物理学 2023-03-01 Supranta S. Boruah , Guilhem Lavaux , Michael J. Hudson

We present a new approach for image reconstruction and weak lensing measurements with interferometers. Based on the shapelet formalism presented in Refregier (2001), object images are decomposed into orthonormal Hermite basis functions. The…

天体物理学 · 物理学 2009-11-06 Tzu-Ching Chang , Alexandre Refregier

The reconstruction of the peculiar velocity field from the 1.936~Jy iras selected sample of galaxies is compared to a similar reconstruction from an optically selected sample. A general method for combining different samples to reconstruct…

天体物理学 · 物理学 2015-06-24 Wolfram Freudling , Luiz Nicolaci da Costa , Paulo S. Pellegrini

Kilometer-scale weather data is crucial for real-world applications but remains computationally intensive to produce using traditional weather simulations. An emerging solution is to use deep learning models, which offer a faster…

Understanding how the physical properties of galaxies (e.g. their spectral type or age) evolve as a function of redshift relies on having an accurate representation of galaxy spectral energy distributions. While it has been known for some…

天体物理学 · 物理学 2009-10-31 Tamas Budavari , Alexander S. Szalay , Andrew J. Connolly , Istvan Csabai , Mark E. Dickinson

Redshift-space clustering distortions provide one of the most powerful probes to test the gravity theory on the largest cosmological scales. We perform a systematic validation study of the state-of-the-art statistical methods currently used…

Redshift-space distortions (RSD) offer an attractive method to measure the growth of cosmic structure on large scales, and combining with the measurement of the cosmic expansion history, it can be used as cosmological tests of gravity. With…

宇宙学与河外天体物理 · 物理学 2014-10-22 Atsushi Taruya , Kazuya Koyama , Takashi Hiramatsu , Akira Oka

Two main strategies have been implemented in mapping the local universe: whole-sky 'shallow' surveys and 'deep' surveys over limited parts of the sky. The two approaches complement each other in studying cosmography and statistical…

天体物理学 · 物理学 2007-05-23 Ofer Lahav

The velocity divergence power spectrum is a key ingredient in modelling redshift space distortion effects on quasi-linear and nonlinear scales. We present an improved model for the z=0 velocity divergence auto and cross power spectrum which…

宇宙学与河外天体物理 · 物理学 2013-05-24 Elise Jennings

Upcoming Large Scale Structure surveys aim to achieve an unprecedented level of precision in measuring galaxy clustering. However, accurately modeling these statistics may require theoretical templates that go beyond second-order…

宇宙学与河外天体物理 · 物理学 2023-11-21 M. Icaza-Lizaola , Yong-Seon Song , Minji Oh , Yi Zheng

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…

天体物理学 · 物理学 2009-11-07 Kohji Yoshikawa , Y. P. Jing , Gerhard Börner

We estimate the power spectrum of mass density fluctuations from peculiar velocities of galaxies by applying an improved maximum-likelihood technique to the new all-sky SFI catalog. Parametric models are used for the power spectrum and the…

Potential features in the primordial power spectrum have been searched for in galaxy surveys in recent years since these features can assist in understanding the nature of inflation. The null detection to date suggests that any such…

宇宙学与河外天体物理 · 物理学 2022-07-01 Yuhao Li , Hong-Ming Zhu , Baojiu Li

Cool giant and supergiant star atmospheres are characterized by complex velocity fields originating from convection and pulsation processes which are not fully understood yet. The velocity fields impact the formation of spectral lines,…

太阳与恒星天体物理 · 物理学 2018-02-21 K. Kravchenko , S. Van Eck , A. Chiavassa , A. Jorissen , B. Freytag , B. Plez

Tests of gravity on large-scales in the universe can be made using both imaging and spectroscopic surveys. The former allow for measurements of weak lensing, galaxy clustering and cross-correlations such as the ISW effect. The latter probe…

宇宙学与河外天体物理 · 物理学 2010-01-27 Jacek Guzik , Bhuvnesh Jain , Masahiro Takada

We use Bayesian inference and nested sampling to develop a non-parametric method to reconstruct the primordial power spectrum $P_{\mathcal{R}}(k)$ from Large Scale Structure (LSS) data. The performance of the method is studied by applying…

宇宙学与河外天体物理 · 物理学 2024-07-16 G. Martínez-Somonte , A. Marcos-Caballero , E. Martínez-González , G. Cañas-Herrera

(abridged) We perform a reconstruction of the cosmological large scale flows in the nearby Universe using two complementary observational sets. The first, the SFI++ sample of Tully-Fisher (TF) measurements of galaxies, provides a direct…

宇宙学与河外天体物理 · 物理学 2015-05-20 Marc Davis , Adi Nusser , Karen Masters , Christopher Springob , John P. Huchra , Gerard Lemson

We present a new class of estimators for computing small-scale power spectra and bispectra in configuration-space via weighted pair- and triple-counts, with no explicit use of Fourier transforms. Particle counts are truncated at $R_0\sim…

宇宙学与河外天体物理 · 物理学 2019-12-30 Oliver H. E. Philcox , Daniel J. Eisenstein

A promising method for measuring the cosmological parameter combination fsigma_8 is to compare observed peculiar velocities with peculiar velocities predicted from a galaxy density field using perturbation theory. We use N-body simulations…

宇宙学与河外天体物理 · 物理学 2021-02-03 Amber M. Hollinger , Michael J. Hudson