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We assess the impact of Galactic synchrotron foreground removal on the observation of high-redshift quasar HII regions in redshifted 21-cm emission. We consider the case where a quasar is observed in an intergalactic medium (IGM) whose…

Astrophysics · Physics 2017-07-24 Paul. M. Geil , Stuart Wyithe , Nada Petrovic , Peng Oh

We investigate the prospect of constraining scalar field dark energy models using HI 21-cm intensity mapping surveys. We consider a wide class of coupled scalar field dark energy models whose predictions about the background cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Azam Hussain , Shruti Thakur , Tapomoy Guha Sarkar , Anjan A Sen

The hybrid interferometer integrating an optical parametric amplifier and a beam splitter has the potential to outperform the SU(1,1) interferometer. However, photon loss remains a critical limitation for practical implementation. To…

Quantum Physics · Physics 2025-10-21 Qisi Zhou , Tao Jiang , Qingqian Kang , Teng Zhao , Xin Su , Cunjin Liu , Liyun Hu

In this paper we describe the spherical harmonic transit telescope, a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved sky complications of traditional interferometry and so is…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-14 J. Richard Shaw , Kris Sigurdson , Ue-Li Pen , Albert Stebbins , Michael Sitwell

We present an end-to-end simulation and data-processing framework for digital beamforming experiments conducted with four stations of the 21 Centimeter Array (21CMA). Motivated by the need to characterize instrumental systematics, such as…

Instrumentation and Methods for Astrophysics · Physics 2026-03-04 Feiyu Zhao , Quan Guo , Junhua Gu , Qian Zheng , Yan Huang , Yun Yu

We present new observations with the Precision Array for Probing the Epoch of Reionization (PAPER) with the aim of measuring the properties of foreground emission for 21cm Epoch of Reionization experiments at 150 MHz. We focus on the…

We propose a fully flexible method to perform an hypothesis test between signal and background based on the Matrix Element Method in the presence of multiple invisible particles. The proposed method performs a mapping of the measured final…

High Energy Physics - Phenomenology · Physics 2018-11-05 Danilo Enoque Ferreira de Lima , Olivier Mattelaer , Michael Spannowsky

Infrared interferometers are optical devices that can measure optical path-length differences by measuring changes in the refractive index. Several arrangements can be deployed, from single channel devices to multichannel double color…

Signal Processing · Electrical Eng. & Systems 2024-02-16 Luis Esteban , Alberto Regadío , Ulises Losada

The 21 cm line of neutral hydrogen is a promising probe of the Epoch of Reionization (EoR) but suffers from contamination by spectrally smooth foregrounds, which obscure the large-scale signal along the line of sight. We explore the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Wenzer Qin , Kai-Feng Chen , Katelin Schutz , Adrian Liu

The 21 cm intensity mapping (IM) technique provides us with an efficient way to observe the cosmic large-scale structure (LSS). From the LSS data, one can use the baryon acoustic oscillation and redshift space distortion to trace the…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-07 Peng-Ju Wu , Yichao Li , Jing-Fei Zhang , Xin Zhang

In this letter, we propose a modified version of Fast Independent Component Analysis (FICA) algorithm to solve the self-interference cancellation (SIC) problem in In-band Full Duplex (IBFD) communication systems. The complex mixing problem…

Signal Processing · Electrical Eng. & Systems 2020-01-07 Mohammed E. Fouda , Sergey Shaboyan , Ayman Elezabi , Ahmed Eltawil

Detecting neutral hydrogen structures in the intergalactic medium (IGM) during cosmic reionization via absorption (21 cm forest) against a background radiation is considered independent and complementary to the three-dimensional tomography…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-10 Nithyanandan Thyagarajan

Statistical observations of the Epoch of Reionization using the 21 cm line of neutral hydrogen have the potential to revolutionize our understanding of structure formation and the first luminous objects. However, these observations are…

Astrophysics · Physics 2008-11-26 Miguel F. Morales , Judd D. Bowman , Jacqueline N. Hewitt

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-27 L. Wolz , F. B. Abdalla , C. Blake , J. R. Shaw , E. Chapman , S. Rawlings

Detecting the global 21 cm signal from the epoch of reionization remains a major observational challenge due to bright foregrounds and instrumental systematics. As part of the Colombian Antarctic Telescopes for 21 cm Absorption during…

We present a method for extracting the expected cosmological 21-cm signal from the epoch of reionization, taking into account contaminating radiations and random instrumental noise. The method is based on the maximum a-posteriori…

Astrophysics · Physics 2008-12-21 Liron Gleser , Adi Nusser , Andrew J. Benson

Unlike single image task, stereo image enhancement can use another view information, and its key stage is how to perform cross-view feature interaction to extract useful information from another view. However, complex noise in low-light…

Computer Vision and Pattern Recognition · Computer Science 2024-01-17 Minghua Zhao , Xiangdong Qin , Shuangli Du , Xuefei Bai , Jiahao Lyu , Yiguang Liu

We discuss absolute calibration strategies for Phase I of the Hydrogen Epoch of Reionization Array (HERA), which aims to measure the cosmological 21 cm signal from the Epoch of Reionization (EoR). HERA is a drift-scan array with a 10 degree…

The 21-cm global signal is obscured by very bright galactic and extra galactic foreground emissions. Typical single-spectrum fit (SSF) based methods for foreground/signal separation can result in biased estimates of the cosmological signal…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-27 Yordan D. Ignatov , Jonathan R. Pritchard