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We present the one-loop 2-point function of biased tracers in redshift space computed with Lagrangian perturbation theory, including a full resummation of both long-wavelength (infrared) displacements and associated velocities. The…

宇宙学与河外天体物理 · 物理学 2021-04-14 Shi-Fan Chen , Zvonimir Vlah , Emanuele Castorina , Martin White

Accurately reconstructing a global spatial field from sparse data has been a longstanding problem in several domains, such as Earth Sciences and Fluid Dynamics. Historically, scientists have approached this problem by employing complex…

计算机视觉与模式识别 · 计算机科学 2024-08-23 Robert Sunderhaft , Logan Frank , Jim Davis

We present a state-of-the-art linear redshift distortion analysis of the recently published IRAS Point Source Catalog Redshift Survey (PSCz). The procedure involves linear compression into 4096 Karhunen-Loeve modes culled from a potential…

天体物理学 · 物理学 2009-10-31 A. J. S. Hamilton , Max Tegmark , Nikhil Padmanabhan

We present a fast iterative FFT-based reconstruction algorithm that allows for non- parallel redshift-space distortions (RSD). We test our algorithm on both N-body dark matter simulations and mock distributions of galaxies designed to…

宇宙学与河外天体物理 · 物理学 2015-08-17 Angela Burden , Will J. Percival , Cullan Howlett

The closely related issues of (1) reconstructing density and velocity fields from redshift survey and distance indicator data and (2) determining cosmological parameters from such data sets are discussed. I focus on possible explanations…

天体物理学 · 物理学 2007-05-23 Jeffrey A. Willick

In massive multiple-input multiple-output (MIMO) downlink systems, the physical implementation of the base stations (BSs) requires the use of cheap and power-efficient power amplifiers (PAs) to avoid high hardware cost and high power…

信号处理 · 电气工程与系统科学 2023-09-04 Yatao Liu , Mingjie Shao , Wing-Kin Ma

We have constrained the redshift-distortion parameter $\beta \equiv \Omega^{0.6}/b$ and the real-space power spectrum of the IRAS PSCz survey using a spherical-harmonic redshift-distortion analysis combined with a data compression method…

天体物理学 · 物理学 2007-05-23 W. E. Ballinger , A. N. Taylor , A. F. Heavens , H. Tadros

We propose a provably convergent method, called Efficient Learned Descent Algorithm (ELDA), for low-dose CT (LDCT) reconstruction. ELDA is a highly interpretable neural network architecture with learned parameters and meanwhile retains…

图像与视频处理 · 电气工程与系统科学 2021-04-28 Qingchao Zhang , Mehrdad Alvandipour , Wenjun Xia , Yi Zhang , Xiaojing Ye , Yunmei Chen

We use a set of large, high-resolution cosmological N-body simulations to examine the redshift-space distortions of galaxy clustering on scales of order 10-200h^{-1} Mpc. Galaxy redshift surveys currently in progress will, on completion,…

天体物理学 · 物理学 2009-06-16 S. J. Hatton , S. Cole

We present a detailed analysis of a new, iterative density reconstruction algorithm. This algorithm uses a decreasing smoothing scale to better reconstruct the density field in Lagrangian space. We implement this algorithm to run on the…

宇宙学与河外天体物理 · 物理学 2024-09-19 Xinyi Chen , Nikhil Padmanabhan

The next generation of galaxy surveys like the Dark Energy Spectroscopic Instrument (DESI) and Euclid will provide datasets orders of magnitude larger than anything available to date. Our ability to model nonlinear effects in late time…

宇宙学与河外天体物理 · 物理学 2021-12-15 Atsuhisa Ota , Hee-Jong Seo , Shun Saito , Florian Beutler

We propose a novel Learned Alternating Minimization Algorithm (LAMA) for dual-domain sparse-view CT image reconstruction. LAMA is naturally induced by a variational model for CT reconstruction with learnable nonsmooth nonconvex…

计算机视觉与模式识别 · 计算机科学 2023-06-07 Chi Ding , Qingchao Zhang , Ge Wang , Xiaojing Ye , Yunmei Chen

We present a novel approach to photometric redshifts, one that merges the advantages of both the template fitting and empirical fitting algorithms, without any of their disadvantages. This technique derives a set of templates, describing…

天体物理学 · 物理学 2009-10-31 I. Csabai , A. J. Connolly , A. S. Szalay , T. Budavari

This paper proposes a tool for dimension reduction where the dimension of the original space is reduced: a Principal Loading Analysis (PLA). PLA is a tool to reduce dimensions by discarding variables. The intuition is that variables are…

统计理论 · 数学 2021-03-05 Jan O. Bauer , Bernhard Drabant

We discuss the extension to redshift space of a rescaling algorithm, designed to alter the effective cosmology of a pre-existing simulated particle distribution or catalogue of dark matter haloes. The rescaling approach was initially…

宇宙学与河外天体物理 · 物理学 2014-11-25 Alexander Mead , John Peacock

We propose a method to reconstruct sparse signals degraded by a nonlinear distortion and acquired at a limited sampling rate. Our method formulates the reconstruction problem as a nonconvex minimization of the sum of a data fitting term and…

最优化与控制 · 数学 2023-01-19 Arthur Marmin , Marc Castella , Jean-Christophe Pesquet , Laurent Duval

The reduced speed of light approximation (RSLA) has been employed to speed up radiative transfer simulations of reionization by a factor of $\gtrsim 5-10$. However, it has been shown to cause significant errors in the HI-ionizing background…

宇宙学与河外天体物理 · 物理学 2024-12-20 Christopher Cain

In this paper, we consider the efficient and robust reconstruction of signals and images via $\ell_{1}-\alpha \ell_{2}~(0<\alpha\leq 1)$ minimization in impulsive noise case. To achieve this goal, we introduce two new models: the…

最优化与控制 · 数学 2018-10-15 Peng Li , Huanmin Ge , Wengu Chen

We present a generalized version of the Path Interchange Zel'dovich Approximation (PIZA; Croft and Gaztanaga 1997; hereafter CG97), which may be used to reconstruct density and velocity fields from realistic galaxy redshift surveys. The…

天体物理学 · 物理学 2007-05-23 Helen E. M. Valentine , Will Saunders , Andy Taylor

We study reconstruction operators on a Hilbert space that are exact on a given reconstruction subspace. Among those the reconstruction operator obtained by the least squares fit has the smallest operator norm, and therefore is most stable…

数值分析 · 数学 2019-09-18 Peter Berger , Karlheinz Gröchenig , Gerald Matz