中文
相关论文

相关论文: Redshift-space density versus real-space velocity …

200 篇论文

We present a new method for recovering the underlying velocity field from an observed distribution of galaxies in redshift space. The method is based on a kinematic Zel'dovich relation between the velocity and density fields in redshift…

天体物理学 · 物理学 2009-10-22 Adi Nusser , Marc Davis

In this work we investigate the nonlinear and nonlocal relation between cosmological density and peculiar velocity fields. Our goal is to provide an algorithm for the recon- struction of the nonlinear velocity field from the fully nonlinear…

宇宙学与河外天体物理 · 物理学 2015-06-03 Francisco-Shu Kitaura , Raul E. Angulo , Yehuda Hoffman , Stefan Gottl"ober

We examine the cosmological redshift-space distortion effect on the power spectrum of the objects at high-redshifts, which is an unavoidable observational contamination in general relativistic cosmology. In particular, we consider the…

天体物理学 · 物理学 2009-10-31 Hiromitsu Magira , Y. P. Jing , Yasushi Suto

We present a maximum probability approach to reconstructing spatial maps of the peculiar velocity field at redshifts $z\sim0.1$, where the velocities have been measured from distance indicators (DI) such as $D_n-\sigma$ relations or…

宇宙学与河外天体物理 · 物理学 2014-11-18 Russell Johnston , David Bacon , Luis F. A. Teodoro , Robert C. Nichol , Michael S. Warren , Catherine Cress

We compare the statistical properties of structures normal and transverse to the line of sight which appear in observational data from redshift surveys. We present a statistic which can quantify this effect in a conceptually different way…

天体物理学 · 物理学 2007-05-23 Hume A. Feldman , Adrian L. Melott

We have used the Optical Redshift Survey (ORS; Santiago et al. 1995) to construct the gravity field due to fluctuations in the galaxy density field out to distances of 8000 km/s. At large scales where linear theory applies, the comparison…

天体物理学 · 物理学 2009-10-30 Jonathan E. Baker , Marc Davis , Michael A. Strauss , Ofer Lahav , Basilio X. Santiago

The relation between the galaxy correlation function in real and redshift-space is derived in the linear regime by an appropriate averaging of the joint probability distribution of density and velocity. The derivation recovers the familiar…

天体物理学 · 物理学 2009-10-22 Karl B. Fisher

We propose a UNet-based deep learning model to reconstruct the real-space dark matter (DM) velocity field from the redshift-space distribution of sparse DM halos. Using various statistical measures, we show that the reconstructed velocity…

宇宙学与河外天体物理 · 物理学 2025-08-26 Xu Xiao , Jiacheng Ding , XiaoLin Luo , Sun Ke Lan , Liang Xiao , Shuai Liu , Xin Wang , Le Zhang , Xiao-Dong Li

The radial component of the peculiar velocities of galaxies cause displacements in their positions in redshift space. We study the effect of the peculiar velocities on the linear redshift space two point correlation function. Our analysis…

天体物理学 · 物理学 2009-10-31 Somnath Bharadwaj

We present a numerical study of the relation between the cosmic peculiar velocity field and the gravitational acceleration field. We show that on mildly non-linear scales (4-10 Mpc Gaussian smoothing), the distribution of the Cartesian…

The distribution of matter that is measured through galaxy redshift and peculiar velocity surveys can be harnessed to learn about the physics of dark matter, dark energy, and the nature of gravity. To improve our understanding of the matter…

宇宙学与河外天体物理 · 物理学 2023-07-04 Fei Qin , David Parkinson , Sungwook E. Hong , Cristiano G. Sabiu

We develop a deep learning technique to infer the non-linear velocity field from the dark matter density field. The deep learning architecture we use is an "U-net" style convolutional neural network, which consists of 15 convolution layers…

宇宙学与河外天体物理 · 物理学 2021-05-21 Ziyong Wu , Zhenyu Zhang , Shuyang Pan , Haitao Miao , Xin Wang , Cristiano G. Sabiu , Jaime Forero-Romero , Yang Wang , Xiao-Dong Li

We present an iterative method to reconstruct the linear-theory initial conditions from the late-time cosmological matter density field, with the intent of improving the recovery of the cosmic distance scale from the baryon acoustic…

宇宙学与河外天体物理 · 物理学 2018-11-05 Ryuichiro Hada , Daniel J. Eisenstein

We present a Bayesian reconstruction method which maps a galaxy distribution from redshift-space to real-space inferring the distances of the individual galaxies. The method is based on sampling density fields assuming a lognormal prior…

We present a new statistic-the redshift dispersion-- which may prove useful for comparing next generation redshift surveys (e.g., the Sloan Digital Sky Survey) and cosmological simulations. Our statistic is specifically designed for the…

天体物理学 · 物理学 2009-10-28 Jeremy Kepner , Frank Summers , Michael Strauss

We rigorously derive weakly nonlinear relation between cosmic density and velocity fields up to third order in perturbation theory. The density field is described by the mass density contrast, $\de$. The velocity field is described by the…

天体物理学 · 物理学 2015-06-24 Michal J. Chodorowski , Ewa L. Lokas

We propose a new velocity reconstruction method based on the displacement estimation by recently developed methods. The velocity is first reconstructed by transfer functions in Lagrangian space and then mapped into Eulerian space. High…

宇宙学与河外天体物理 · 物理学 2020-01-01 Yu Yu , Hong-Ming Zhu

The peculiar velocities of galaxies distort the pattern of galaxy clustering in redshift space, making the redshift space power spectrum anisotropic. In the linear regime, the strength of this distortion depends only on the ratio $\beta…

天体物理学 · 物理学 2015-06-24 Shaun Cole , Karl B. Fisher , David H. Weinberg

Untangling the connection between redshift space coordinates, a velocity measurement, and three dimensional real space coordinates, is a cosmological problem that is often modeled through a linear understanding of the velocity-position…

宇宙学与河外天体物理 · 物理学 2025-02-05 Emily Tyhurst , Hamsa Padmanabhan , Ue-Li Pen

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)…

天体物理学 · 物理学 2009-11-06 Xiao-Hu Yang , Long-Long Feng , Yao-Quan Chu , Li-Zhi Fang