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Primordial non-Gaussianity is a crucial test of inflationary cosmology. We consider the impact of non-Gaussianity on the ionization power spectrum from 21 cm emission during the epoch of reionization. We focus on the power spectrum on large…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-30 Shahab Joudaki , Olivier Dore , Luis Ferramacho , Manoj Kaplinghat , Mario G. Santos

During the epoch of reionization (EoR), the 21-cm signal allows direct observation of the neutral hydrogen (HI) in the intergalactic medium (IGM). In the post-reionization era, this signal instead probes HI in galaxies, which traces the…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-20 Sambit K. Giri , Michele Bianco , Timothée Schaeffer , Ilian T. Iliev , Garrelt Mellema , Aurel Schneider

Detection of the \hi~ 21-cm power spectrum is one of the key science drivers of several ongoing and upcoming low-frequency radio interferometers. However, the major challenge in such observations come from bright foregrounds, whose accurate…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-29 Madhurima Choudhury , Abhirup Datta , Suman Majumdar

A number of radio interferometers are currently being planned or constructed to observe 21 cm emission from reionization. Not only will such measurements provide a detailed view of that epoch, but, since the 21 cm emission also traces the…

In this paper, we propose a novel method to recover the 21cm global signal from the 21cm power spectrum using artificial neural networks (ANNs). The 21cm global signal is crucial for understanding cosmic evolution from the Dark Ages through…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Hayato Shimabukuro

We study the viability of using power spectrum clustering wedges as summary statistics of 21cm surveys during the Epoch of Reionization (EoR). For observations in a wide redshift range $z\sim 7-9$ corresponding to a line-of-sight scale of…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-31 Zhaoting Chen , Alkistis Pourtsidou

Neutral hydrogen (HI) serves as a crucial probe for the Cosmic Dawn and the Epoch of Reionization (EoR). Actual observations of the 21-cm signal often encounter challenges such as thermal noise and various systematic effects. To overcome…

The 21cm signal of neutral hydrogen contains a wealth of information about the poorly constrained era of cosmological history, the Epoch of Reionization (EoR). Recently, AI models trained on EoR simulations have gained significant attention…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-08 Jasper Solt , Jonathan C. Pober , Stephen H. Bach

We present new constraints on parameters of cosmic dawn and the epoch of reionization derived from the EDGES High-Band spectrum ($90-190$ MHz). The parameters are probed by evaluating global $21$ cm signals generated with the recently…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Raul A. Monsalve , Anastasia Fialkov , Judd D. Bowman , Alan E. E. Rogers , Thomas J. Mozdzen , Aviad Cohen , Rennan Barkana , Nivedita Mahesh

The redshifted cosmological 21 cm signal emitted by neutral hydrogen during the first billion years of the universe is much fainter relative to other galactic and extragalactic radio emissions, posing a great challenge towards detection of…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-26 J. Kariuki Chege , C. H. Jordan , C. Lynch , C. M. Trott , J. L. B. Line , B. Pindor , S. Yoshiura

Structure imprinted in foreground extragalactic point sources by ionospheric refraction has the potential to contaminate Epoch of Reionisation (EoR) power spectra of the 21~cm emission line of neutral hydrogen. The alteration of the spatial…

We explore error distributions in Epoch of Reionization 21-cm power spectrum estimators using a combination of mathematical analysis and numerical simulations. We provide closed form solutions for the error distributions of individual bins…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-20 Michael J. Wilensky , Jordan Brown , Bryna J. Hazelton

(Abridged) Noise considerations for experiments that aim to statistically estimate the 21 cm signal from high redshift neutral hydrogen during the Epoch of Reionisation (EoR) using interferometric data are typically computed assuming a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Cathryn M. Trott

The light-cone (LC) effect causes the Epoch of Reionization (EoR) 21-cm signal $T_{\rm b} (\hat{\bf{n}}, \nu)$ to evolve significantly along the line of sight (LoS) direction $\nu$. In the first part of this paper, we present a method to…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-12 Rajesh Mondal , Somnath Bharadwaj , Kanan K. Datta

Radio interferometers, such as the Low-Frequency Array and the future Square Kilometre Array, are attempting to measure the spherically averaged 21-cm power spectrum from the Epoch of Reionization. Understanding of the dominant physical…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Ivelin Georgiev , Garrelt Mellema , Sambit K. Giri , Rajesh Mondal

The redshifted 21cm signal from the post-reionization epoch is highly non-Gaussian; thus, higher-order statistics, such as the bispectrum, are required to extract this non-Gaussian information. However, high-signal-to-noise ratio detection…

Observations of redshifted 21-cm radiation from neutral hydrogen during the epoch of reionization (EoR) are considered to constitute the most promising tool to probe that epoch. One of the major goals of the first generation of low…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Kanan K. Datta , Garrelt Mellema , Yi Mao , Ilian T. Iliev , Paul R. Shapiro , Kyungjin Ahn

The high redshift 21-cm signal promises to be a crucial probe of the state of the intergalactic medium (IGM). Understanding the connection between the observed 21-cm power spectrum and the physical quantities intricately associated with the…

We quantify the effect of radio frequency interference (RFI) on measurements of the 21-cm power spectrum during the Epoch of Reionization (EoR). Specifically, we investigate how the frequency structure of RFI source emission generates…

Instrumentation and Methods for Astrophysics · Physics 2020-09-09 Michael J. Wilensky , Nichole Barry , Miguel F. Morales , Bryna J. Hazelton , Ruby Byrne

Observation of multifrequency angular power spectrum of the redshifted 21-cm brightness temperature fluctuation from the neutral hydrogen holds the key to understand the structure formation and its evolution during the reionization and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-28 Saikat Gayen , Jais Kumar , Prasun Dutta , Khandakar Md Asif Elahi , Samir Choudhuri , Nirupam Roy
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