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We compare various foreground removal techniques that are being utilised to remove bright foregrounds in various experiments aiming to detect the redshifted 21cm signal of neutral hydrogen from the Epoch of Reionization. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-17 Ian Hothi , Emma Chapman , Jonathan R. Pritchard , F. G. Mertens , L. V. E Koopmans , B. Ciardi , B. K. Gehlot , R. Ghara , A. Ghosh , S. K. Giri , I. T. Iliev , V. Jelić , S. Zaroubi

The cosmic microwave background (CMB) is a significant source of knowledge about the origin and evolution of our universe. However, observations of the CMB are contaminated by foreground emissions, obscuring the CMB signal and reducing its…

Machine Learning · Computer Science 2023-02-27 Jadie Adams , Steven Lu , Krzysztof M. Gorski , Graca Rocha , Kiri L. Wagstaff

We extend to large scales a method proposed in previous work that reconstructs non-parametrically the primordial power spectrum from cosmic microwave background data at high resolution. The improvement is necessary to account for the…

Astrophysics · Physics 2009-11-13 Domenico Tocchini-Valentini , Yehuda Hoffman , Joseph Silk

We describe an exact, flexible, and computationally efficient algorithm for a joint estimation of the large-scale structure and its power-spectrum, building on a Gibbs sampling framework and present its implementation ARES (Algorithm for…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 J. Jasche , F. S. Kitaura , B. D. Wandelt , T. A. Ensslin

We derive and implement a full Bayesian large scale structure inference method aiming at precision recovery of the cosmological power spectrum from galaxy redshift surveys. Our approach improves over previous Bayesian methods by performing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Jens Jasche , Benjamin D. Wandelt

High-fidelity spectrum cartography is pivotal for spectrum management and wireless situational awareness, yet it remains a challenging ill-posed inverse problem due to the sparsity and irregularity of observations. Furthermore, existing…

Information Theory · Computer Science 2025-12-24 Yuntong Gu , Xiangming meng , Zhiyuan Lin , Sheng Wu , Linling Kuang

In signal processing, the data collected from sensing devices is often a noisy linear superposition of multiple components, and the estimation of components of interest constitutes a crucial pre-processing step. In this work, we develop a…

Signal Processing · Electrical Eng. & Systems 2026-02-12 Yi Zhang , Rui Guo , Yonina C. Eldar

Accurate beam modeling is important in many radio astronomy applications. In this paper, we focus on beam modeling for 21-cm intensity mapping experiments using radio interferometers, though the techniques also apply to single dish…

Instrumentation and Methods for Astrophysics · Physics 2025-09-16 Michael J. Wilensky , Philip Bull , Nicolas Fagnoni

Missing channels in radio-interferometric visibility data can introduce systematic artifacts into the estimated 21-cm power spectrum. A common workaround is to first estimate the two-frequency correlation $C(\Delta\nu)$ and then…

Instrumentation and Methods for Astrophysics · Physics 2026-03-27 Khandakar Md Asif Elahi

Current and future Cosmic Microwave Background (CMB) experiments aim to achieve high-precision reconstruction of the CMB polarization signal, with the most ambitious objective being the detection of primordial $B$ modes sourced by cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 Alessandro Carones

The extraction of the sky-averaged 21 cm signal from Cosmic Dawn and the Epoch of Reionization faces significant challenges. The bright and anisotropic Galactic foreground, which is 4 - 5 orders of magnitude brighter than the 21 cm signal,…

Instrumentation and Methods for Astrophysics · Physics 2025-12-10 Haoran Li , Furen Deng , Meng Zhou , Yidong Xu , Xuelei Chen

We assess the performance of the multipole expansion formalism in the case of single-dish HI intensity mapping, including instrumental and foreground removal effects. This formalism is used to provide MCMC forecasts for a range of HI and…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Paula S. Soares , Steven Cunnington , Alkistis Pourtsidou , Chris Blake

This paper presents a hierarchical Bayesian model to reconstruct sparse images when the observations are obtained from linear transformations and corrupted by an additive white Gaussian noise. Our hierarchical Bayes model is well suited to…

Data Analysis, Statistics and Probability · Physics 2011-01-19 Nicolas Dobigeon , Alfred O. Hero , Jean-Yves Tourneret

We implement and further refine the recently proposed method (Kashlinsky, Hern\'andez-Monteagudo & Atrio-Barandela, 2001 - KHA) for a time efficient extraction of the power spectrum from future cosmic microwave background (CMB) maps. The…

Astrophysics · Physics 2009-11-07 C. Hernandez-Monteagudo , A. Kashlinsky , F. Atrio-Barandela

We present a Bayesian framework to establish a power-spectrum space decomposition of frequency tomographic (PSDFT) data for future intensity mapping (IM) experiments. Different from most traditional component-separation methods which work…

Instrumentation and Methods for Astrophysics · Physics 2023-08-30 Chang Feng , Filipe B. Abdalla

We present a novel computational approach for extracting weak signals, whose exact location and width may be unknown, from complex background distributions with an arbitrary functional form. We focus on datasets that can be naturally…

High Energy Physics - Experiment · Physics 2023-03-22 Abhijith Gandrakota , Amitabh Lath , Alexandre V. Morozov , Sindhu Murthy

The form of the primordial power spectrum has the potential to differentiate strongly between competing models of perturbation generation in the early universe and so is of considerable importance. The recent release of five years of WMAP…

Astrophysics · Physics 2015-05-13 M. Bridges , F. Feroz , M. P. Hobson , A. N. Lasenby

Simulated observations of a $10\dg \times 10\dg$ field by the Microwave Anisotropy Probe (MAP) are analysed in order to separate cosmic microwave background (CMB) emission from foreground contaminants and instrumental noise and thereby…

Astrophysics · Physics 2009-10-31 A. W. Jones , M. P. Hobson , A. N. Lasenby

The 21-cm forest, comprising narrow absorption features imprinted on the radio spectra of high-redshift radio-loud quasars by intervening neutral hydrogen, offers a uniquely sensitive probe of the thermal state of the neutral intergalactic…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-25 Sameer K. Patil , Tomáš Šoltinský , Soumak Maitra , Girish Kulkarni

Gaussian time-series models are often specified through their spectral density. Such models present several computational challenges, in particular because of the non-sparse nature of the covariance matrix. We derive a fast approximation of…

Computation · Statistics 2012-11-20 Nicolas Chopin , Judith Rousseau , Brunero Liseo