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We reconstruct the underlying density field of the 2 degree Field Galaxy Redshift Survey (2dFGRS) for the redshift range 0.035<z<0.200 using the Wiener Filtering method. The Wiener Filter suppresses shot noise and accounts for selection and…

We quantify the performance of a non-linear Wiener filter, constructed in wavelet space, at recovering some of the Fisher information that was lost in the weak lensing convergence field. The proposed method consists in a separation of the…

宇宙学与河外天体物理 · 物理学 2011-12-16 Hao-Ran Yu , Joachim Harnois-Déraps , Tong-Jie Zhang , Ue-Li Pen

We study the cosmological information contained in the Minkowski Functionals (MFs) of weak gravitational lensing convergence maps. We show that the MFs provide strong constraints on the local type primordial non-Gaussianity parameter f_NL.…

宇宙学与河外天体物理 · 物理学 2015-06-04 Masato Shirasaki , Naoki Yoshida , Takashi Hamana , Takahiro Nishimichi

We apply a mass reconstruction technique to simulated large-scale structure gravitational distortion maps, from 2.5' to 10 degree scales, for different cosmological scenarii. The projected mass is reconstructed using a non-parametric least…

天体物理学 · 物理学 2007-05-23 L. Van Waerbeke , F. Bernardeau , Y. Mellier

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and optical/near-IR bands for mitigating systematic effects. We…

宇宙学与河外天体物理 · 物理学 2018-09-19 Stefano Camera , Ian Harrison , Anna Bonaldi , Michael L. Brown

Cosmic shear data contains a large amount of cosmological information encapsulated in the non-Gaussian features of the weak lensing mass maps. This information can be extracted using non-Gaussian statistics. We compare the constraining…

宇宙学与河外天体物理 · 物理学 2021-01-20 Dominik Zürcher , Janis Fluri , Raphael Sgier , Tomasz Kacprzak , Alexandre Refregier

We propose a new mass-mapping algorithm, specifically designed to recover small-scale information from a combination of gravitational shear and flexion. Including flexion allows us to supplement the shear on small scales in order to…

宇宙学与河外天体物理 · 物理学 2016-06-08 Francois Lanusse , Jean-Luc Starck , Adrienne Leonard , Sandrine Pires

Reconstruction of images from noisy linear measurements is a core problem in image processing, for which convex optimization methods based on total variation (TV) minimization have been the long-standing state-of-the-art. We present an…

信息论 · 计算机科学 2016-08-31 Jean Barbier , Eric W. Tramel , Florent Krzakala

Recovering credible cosmological parameter constraints in a weak lensing shear analysis requires an accurate model that can be used to marginalize over nuisance parameters describing potential sources of systematic uncertainty, such as the…

宇宙学与河外天体物理 · 物理学 2023-04-20 Tianqing Zhang , Markus Michael Rau , Rachel Mandelbaum , Xiangchong Li , Ben Moews

In this paper we provide a statistical analysis of the parameter-free method often used in weak lensing mass reconstructions. It is found that a proper assessment of the errors involved in such a non-local analysis requires the study of the…

天体物理学 · 物理学 2007-05-23 Marco Lombardi , Giuseppe Bertin

Cosmic shear - the weak gravitational lensing effect generated by fluctuations of the gravitational tidal fields of the large-scale structure - is one of the most promising tools for current and future cosmological analyses. The…

宇宙学与河外天体物理 · 物理学 2018-11-14 A. Spurio Mancini , P. L. Taylor , R. Reischke , T. Kitching , V. Pettorino , B. M. Schäfer , B. Zieser , Ph. M. Merkel

Kaiser & Squires have proposed a technique for mapping the dark matter in galaxy clusters using the coherent weak distortion of background galaxy images caused by gravitational lensing. We investigate the effectiveness of this technique…

天体物理学 · 物理学 2015-06-24 Gillian Wilson , Shaun Cole , Carlos S. Frenk

Weak gravitational lensing is an invaluable tool for understanding fundamental cosmological physics. An unresolved issue in weak lensing cosmology is to accurately reconstruct the lensing convergence $\kappa$ maps from discrete shear…

宇宙学与河外天体物理 · 物理学 2024-06-25 Yuan Shi , Pengjie Zhang , Zeyang Sun , Yihe Wang

We propose an algorithm for the reconstruction of the signal induced by cosmic strings in the cosmic microwave background (CMB), from radio-interferometric data at arcminute resolution. Radio interferometry provides incomplete and noisy…

宇宙学与河外天体物理 · 物理学 2015-05-14 Y. Wiaux , G. Puy , P. Vandergheynst

We present a new method to extract cosmological constraints from weak lensing (WL) peak counts, which we denote as `the hierarchical algorithm'. The idea of this method is to combine information from WL maps sequentially smoothed with a…

宇宙学与河外天体物理 · 物理学 2015-05-30 Laura Marian , Robert E. Smith , Stefan Hilbert , Peter Schneider

We consider a compressive hyperspectral imaging reconstruction problem, where three-dimensional spatio-spectral information about a scene is sensed by a coded aperture snapshot spectral imager (CASSI). The approximate message passing (AMP)…

信息论 · 计算机科学 2015-09-09 Jin Tan , Yanting Ma , Hoover Rueda , Dror Baron , Gonzalo Arce

Weak lensing observations measure the shear field and hence the gradient of the dimensionless surface density $\kappa$. We present several new algorithms to recover $\kappa$ {}from shear estimates on a finite region and compare how they…

天体物理学 · 物理学 2009-10-28 Gordon Squires , Nick Kaiser

The reconstruction of the density profile in clusters of galaxies from the distortion of the images of faint background galaxies is reconsidered. The inversion formula of Kaiser \& Squires is known to provide a quantitative way to perform…

天体物理学 · 物理学 2007-05-23 Peter Schneider

This paper presents a deep learning method for faster magnetic resonance imaging (MRI) by reducing k-space data with sub-Nyquist sampling strategies and provides a rationale for why the proposed approach works well. Uniform subsampling is…

机器学习 · 统计学 2019-05-14 Chang Min Hyun , Hwa Pyung Kim , Sung Min Lee , Sungchul Lee , Jin Keun Seo

Reconstruction techniques are commonly used in cosmology to reduce complicated nonlinear behaviours to a more tractable linearized system. We study a new reconstruction technique that uses the Moving-Mesh algorithm to estimate the…

宇宙学与河外天体物理 · 物理学 2017-06-21 Qiaoyin Pan , Ue-Li Pen , Derek Inman , Hao-Ran Yu