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Neutral hydrogen intensity mapping can in principle deliver rapid and large-volume cosmological surveys with exquisitely accurate redshifts that are determined directly from imaging. However, intensity maps suffer from very strong…

宇宙学与河外天体物理 · 物理学 2024-05-30 Rahul Kothari , Roy Maartens

HI intensity mapping is an emerging tool to probe dark energy. Observations of the redshifted HI signal will be contaminated by instrumental noise, atmospheric and Galactic foregrounds. The latter is expected to be four orders of magnitude…

宇宙学与河外天体物理 · 物理学 2015-10-28 M. -A. Bigot-Sazy , C. Dickinson , R. A. Battye , I. W. A. Browne , Y. -Z. Ma , B. Maffei , F. Noviello , M. Remazeilles , P. N. Wilkinson

The future of precision cosmology could benefit from cross-correlations between intensity maps of unresolved neutral hydrogen (HI) and more conventional optical galaxy surveys. A major challenge that needs to be overcome is removing the…

宇宙学与河外天体物理 · 物理学 2019-07-17 Steven Cunnington , Laura Wolz , Alkistis Pourtsidou , David Bacon

The success of HI intensity mapping is largely dependent on how well 21cm foreground contamination can be controlled. In order to progress our understanding further, we present a range of simulated foreground data from four different…

宇宙学与河外天体物理 · 物理学 2021-03-25 Steven Cunnington , Melis O. Irfan , Isabella P. Carucci , Alkistis Pourtsidou , Jérôme Bobin

Upcoming and future neutral hydrogen Intensity Mapping surveys offer a great opportunity to constrain cosmology in the post-reionization Universe, provided a good accuracy is achieved in the separation between the strong foregrounds and the…

宇宙学与河外天体物理 · 物理学 2021-09-02 Siyambonga D. Matshawule , Marta Spinelli , Mario G. Santos , Sibonelo Ngobese

The deep learning technique has been employed in removing foreground contaminants from 21 cm intensity mapping, but its effectiveness is limited by the large dynamic range of the foreground amplitude. In this study, we develop a novel…

宇宙学与河外天体物理 · 物理学 2024-03-13 Feng Shi , Haoxiang Chang , Le Zhang , Huanyuan Shan , Jiajun Zhang , Suiping Zhou , Ming Jiang , Zitong Wang

We conduct the first case study towards developing optimal foreground mitigation strategies for neutral hydrogen (HI) intensity mapping using radio interferometers at low redshifts. A pipeline for simulation, foreground mitigation and power…

宇宙学与河外天体物理 · 物理学 2022-12-08 Zhaoting Chen , Laura Wolz , Richard Battye

A goal for pathfinder intensity mapping (IM) surveys will be detecting features in the neutral hydrogen (HI) power spectrum, which serve as conclusive evidence of cosmological signals. Observing such features at the expected scales in HI IM…

宇宙学与河外天体物理 · 物理学 2022-03-25 Steven Cunnington

We model a 21 cm intensity mapping survey in the redshift range 0.01<z<1.5 designed to simulate the skies as seen by future radio telescopes such as the Square Kilometre Array (SKA), including instrumental noise and Galactic foregrounds. In…

宇宙学与河外天体物理 · 物理学 2015-03-27 L. Wolz , F. B. Abdalla , C. Blake , J. R. Shaw , E. Chapman , S. Rawlings

Neutral hydrogen (HI) intensity mapping with single-dish experiments is a powerful approach for probing cosmology in the post-reionization epoch. However, the presence of bright foregrounds over four orders of magnitude stronger than the HI…

宇宙学与河外天体物理 · 物理学 2026-02-03 Athanasia Gkogkou , Victor Bonjean , Jean-Luc Starck , Marta Spinelli , Panagiotis Tsakalides

This work presents a joint and self-consistent Bayesian treatment of various foreground and target contaminations when inferring cosmological power-spectra and three dimensional density fields from galaxy redshift surveys. This is achieved…

宇宙学与河外天体物理 · 物理学 2017-10-11 Jens Jasche , Guilhem Lavaux

21-cm intensity mapping (IM) is a powerful technique to probe the large-scale distribution of neutral hydrogen (HI) and extract cosmological information such as the baryon acoustic oscillation feature. A key challenge lies in recovering the…

宇宙学与河外天体物理 · 物理学 2025-11-24 Zitong Wang , Feng Shi , Le Zhang , Yanming Liu , Xiaoping Li , Shulei Ni , Ming Jiang , Xiaofan Ma

Deconvolution is a fundamental inverse problem in signal processing and the prototypical model for recovering a signal from its noisy measurement. Nevertheless, the majority of model-based inversion techniques require knowledge on the…

信号处理 · 电气工程与系统科学 2020-07-23 Arttu Arjas , Lassi Roininen , Mikko J. Sillanpää , Andreas Hauptmann

Upcoming 21-cm intensity surveys will use the hyperfine transition in emission to map out neutral hydrogen in large volumes of the universe. Unfortunately, large spatial scales are completely contaminated with spectrally smooth…

宇宙学与河外天体物理 · 物理学 2019-11-27 Chirag Modi , Martin White , Anze Slosar , Emanuele Castorina

Potential evidence for primordial non-Gaussianity (PNG) is expected to lie in the largest scales mapped by cosmological surveys. Forthcoming 21cm intensity mapping experiments will aim to probe these scales by surveying neutral hydrogen…

宇宙学与河外天体物理 · 物理学 2020-10-20 Steven Cunnington , Stefano Camera , Alkistis Pourtsidou

21cm tomography promises to be a powerful tool for estimating cosmological parameters, constraining the epoch of reionization, and probing the so-called dark ages. However, realizing this promise will require the extraction of a…

宇宙学与河外天体物理 · 物理学 2011-06-02 Adrian Liu , Max Tegmark

Next-generation spectroscopic surveys will map the large-scale structure of the observable universe, using emission line galaxies as tracers. While each survey will map the sky with a specific emission line, interloping emission lines can…

宇宙学与河外天体物理 · 物理学 2016-04-20 Anthony R. Pullen , Christopher M. Hirata , Olivier Dore , Alvise Raccanelli

The bispectrum is a 3-point statistic with the potential to provide additional information beyond power spectra analyses of survey datasets. Radio telescopes which broadly survey the 21cm emission from neutral hydrogen (HI) are a promising…

宇宙学与河外天体物理 · 物理学 2021-08-11 Steven Cunnington , Catherine Watkinson , Alkistis Pourtsidou

Quantitative susceptibility mapping (QSM) utilizes MRI signal phase to estimate local tissue susceptibility, which has been shown useful to provide novel image contrast and as biomarkers of abnormal tissue. QSM requires addressing a…

医学物理 · 物理学 2019-06-03 Juan Liu , Kevin M. Koch

One popular approach for blind deconvolution is to formulate a maximum a posteriori (MAP) problem with sparsity priors on the gradients of the latent image, and then alternatingly estimate the blur kernel and the latent image. While several…

计算机视觉与模式识别 · 计算机科学 2017-08-29 Sunghyun Cho , Seungyong Lee
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