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An improved method for subtracting contaminants from Cosmic Microwave Background (CMB) sky maps is presented, and used to estimate how well future experiments will be able to recover the primordial CMB fluctuations. We find that the naive…

Astrophysics · Physics 2015-06-24 Max Tegmark , George Efstathiou

Intensity mapping of 21cm emission from neutral hydrogen promises to be a powerful probe of large-scale structure in the post-reionisation epoch. However, HI intensity mapping (IM) experiments will suffer the loss of long-wavelength…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-30 Kavilan Moodley , Warren Naidoo , Heather Prince , Aurelie Penin

The key challenge in the observation of the redshifted 21-cm signal from cosmic reionization is its separation from the much brighter foreground emission. Such separation relies on the different spectral properties of the two components,…

Hydrogen intensity mapping is a new field in astronomy that promises to make three-dimensional maps of the matter distribution of the Universe using the redshifted $21\,\textrm{cm}$ line of neutral hydrogen gas (HI). Several ongoing and…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Anh Phan , Santanu Das , Albert Stebbins , Peter Timbie , Reza Ansari , Shifan Zuo , Jixia Li , Trevor Oxholm , Fengquan Wu , Xuelei Chen , Shijie Sun , Yougang Wang , Jiao Zhang

We investigate the possibility of performing cosmological studies in the redshift range $2.5<z<5$ through suitable extensions of existing and upcoming radio-telescopes like CHIME, HIRAX and FAST. We use the Fisher matrix technique to…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-11 Andrej Obuljen , Emanuele Castorina , Francisco Villaescusa-Navarro , Matteo Viel

The 21 cm radiation of neutral hydrogen provides crucial information for studying the early universe and its evolution. To advance this research, countries have made significant investments in constructing large low-frequency radio…

Instrumentation and Methods for Astrophysics · Physics 2025-08-04 Ming-wei Qin , Rui Tang , Ying-hui Zhou , Chang-jun Lan , Wen-hao Fu , Huan Wang , Bao-lin Hou , Zamri , Jin-song Ping , Wen-jun Yang , Liang Dong

This paper proposes a foreground-background separation (FBS) method with a novel foreground model based on convolutional sparse representation (CSR). In order to analyze the dynamic and static components of videos acquired under undesirable…

Computer Vision and Pattern Recognition · Computer Science 2025-06-24 Kazuki Naganuma , Shunsuke Ono

Instruments targeting 21~cm emission at high redshifts need a spectral dynamic range of better than ten thousand to distinguish the 21~cm background against bright foregrounds. Systematics arising from the antenna pattern are a leading…

Instrumentation and Methods for Astrophysics · Physics 2026-05-21 Daniel C. Jacobs

Future high redshift 21-cm experiments will suffer from a high degree of contamination, due both to astrophysical foregrounds and to non-astrophysical and instrumental effects. In order to reliably extract the cosmological signal from the…

Optical aberrations prevent telescopes from reaching their theoretical diffraction limit. Once estimated, these aberrations can be compensated for using deformable mirrors in a closed loop. Focal plane wavefront sensing enables the…

Many post-processing algorithms have been developed in order to better separate the signal of a companion from the bright light of the host star, but the effect of such algorithms on the shape of exoplanet spectra extracted from integral…

Earth and Planetary Astrophysics · Physics 2023-10-04 Evert Nasedkin , Paul Mollière , Jason Wang , Faustine Cantalloube , Laura Kreidberg , Laurent Pueyo , Tomas Stolker , Arthur Vigan

One of the primary challenges in enabling the scientific potential of 21 cm intensity mapping at the Epoch of Reionization (EoR) is the separation of astrophysical foreground contamination. Recent works have claimed that Gaussian process…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-29 Nicholas Kern , Adrian Liu

A successful detection of the cosmological 21-cm signal from intensity mapping experiments (for example, during the Epoch of Reioinization or Cosmic Dawn) is contingent on the suppression of subtle systematic effects in the data. Some of…

This paper presents a deep learning-based framework for enhancing radar systems in the presence of interference, leveraging Reconfigurable Intelligent Surfaces (RIS). The proposed technique uses a modified MUSIC algorithm to estimate the…

Signal Processing · Electrical Eng. & Systems 2025-04-08 Ali Parchekani , Milad Johnny , Shahrokh Valaee

Transformer-based image restoration methods in adverse weather have achieved significant progress. Most of them use self-attention along the channel dimension or within spatially fixed-range blocks to reduce computational load. However,…

Computer Vision and Pattern Recognition · Computer Science 2024-07-26 Shangquan Sun , Wenqi Ren , Xinwei Gao , Rui Wang , Xiaochun Cao

We reconsider the pixel-based, "template" polarized foreground removal method within the context of a next-generation, low-noise, low-resolution (0.5 degree FWHM) space-borne experiment measuring the cosmological B-mode polarization signal…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Nobuhiko Katayama , Eiichiro Komatsu

Low-frequency radio observatories are reaching unprecedented levels of sensitivity in an effort to detect the 21 cm signal from the Cosmic Dawn. High precision is needed because the expected signal is overwhelmed by foreground…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Adam E. Lanman , Steven G. Murray , Daniel C. Jacobs

Observations with the Canadian Hydrogen Intensity Mapping Experiment (CHIME) have been used to measure the 21 cm intensity mapping auto power spectrum, at $z\sim 1$, over a frequency range from 608.2 MHz to 707.8 MHz at wavenumbers…

Intelligent reflecting surface (IRS) has gained great attention for its ability to create favorable propagation environments. However, the power consumption of conventional IRSs cannot be ignored due to the large number of reflecting…

Signal Processing · Electrical Eng. & Systems 2025-06-13 Weibiao Zhao , Qiucen Wu , Yuanqi Tang , Yu Zhu

Purpose: Field monitoring measures field perturbations, which can be accounted for during image reconstructions. In certain field monitoring environments, significant phase deviations can arise far from isocenter due to the finite extent of…

Medical Physics · Physics 2023-01-25 Paul I. Dubovan , Kyle M. Gilbert , Corey A. Baron