English
Related papers

Related papers: Recovering Cosmic Structure with a Simple Physical…

200 papers

We introduce a new implementation of the FastICA algorithm on simulated LOFAR EoR data with the aim of accurately removing the foregrounds and extracting the 21-cm reionization signal. We find that the method successfully removes the…

21 cm tomography is expected to be difficult in part because of serious foreground contamination. Previous studies have found that line-of-sight approaches are capable of cleaning foregrounds to an acceptable level on large spatial scales,…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-05 Adrian Liu , Max Tegmark , Judd Bowman , Jacqueline Hewitt , Matias Zaldarriaga

Optimal transport theory has recently reemerged as a vastly resourceful field of mathematics with elegant applications across physics and computer science. Harnessing methods from geometry processing, we report on the efficient…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Sebastian von Hausegger , Bruno Lévy , Roya Mohayaee

In this paper, we present a novel approach to the estimation of strongly varying backgrounds in astronomical images by means of small objects removal and subsequent missing pixels interpolation. The method is based on the analysis of a…

Instrumentation and Methods for Astrophysics · Physics 2016-08-10 Adam Popowicz , Bogdan Smolka

The primordial stochastic gravitational wave background (SGWB) carries first-hand messages of early-universe physics, possibly including effects from inflation, preheating, cosmic strings, electroweak symmetry breaking, and etc. However,…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-16 Zhen Pan , Huan Yang

The present work is based on a parametric reconstruction of the deceleration parameter $q(z)$ in a model for the spatially flat FRW universe filled with dark energy and non-relativistic matter. In cosmology, the parametric reconstruction…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Abdulla Al Mamon , Sudipta Das

Baryon acoustic oscillations (BAO) underpin the key cosmological results from modern spectroscopic galaxy surveys, but nonlinear gravitational evolution limits the precision achievable with traditional analysis methods. To overcome this, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Adrian E. Bayer , Liam Parker , David Valcin , Shi-Fan Chen , Chirag Modi , Uros Seljak

Our ability to extract the maximal amount of information from future observations at gigahertz frequencies depends on our ability to separate the underlying cosmic microwave background (CMB) from galactic and extragalactic foregrounds. We…

Astrophysics · Physics 2007-05-23 J. Jewell , C. R. Lawrence , S. Levin

Characterizing the epoch of reionization (EoR) at $z\gtrsim 6$ via the redshifted 21 cm line of neutral Hydrogen (HI) is critical to modern astrophysics and cosmology, and thus a key science goal of many current and planned low-frequency…

Acoustic waves traveling through the early Universe imprint a characteristic scale in the clustering of galaxies, QSOs and inter-galactic gas. This scale can be used as a standard ruler to map the expansion history of the Universe, a…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 J. D. Cohn , Martin White , Tzu-Ching Chang , Gil Holder , Nikhil Padmanabhan , Olivier Doré

This paper presents a systematic literature review focusing on the application of machine learning techniques for deriving observational constraints in cosmology. The goal is to evaluate and synthesize existing research to identify…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-14 Luis Rojas , Sebastián Espinoza , Esteban González , Carlos Maldonado , Fei Luo

The observation of space-time variations in fundamental constants would provide strong evidence for the existence of new light degrees of freedom in the theory of Nature. Robustly constraining such scenarios requires exploiting observations…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-17 Laura Lopez-Honorez , Olga Mena , Sergio Palomares-Ruiz , Pablo Villanueva-Domingo , Samuel J. Witte

Global 21cm cosmology aims to investigate the cosmic dawn and epoch of reionisation by measuring the sky averaged HI absorption signal, which requires, accurate modelling of, or correction for, the bright radio foregrounds and distortions…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 Dominic Anstey , Eloy de Lera Acedo , Will Handley

Photometric surveys have provided incredible amounts of astronomical information in the form of images. However, astronomical images often contain artifacts that can critically hinder scientific analysis by misrepresenting intensities or…

Instrumentation and Methods for Astrophysics · Physics 2020-06-03 Suchetha Cooray , Tsutomu T. Takeuchi , Moe Yoda , Kazuo Sorai

We perform an analysis of the three-dimensional cosmic matter density field traced by galaxies of the SDSS-III/BOSS galaxy sample. The systematic-free nature of this analysis is confirmed by two elements: the successful cross-correlation…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-17 Guilhem Lavaux , Jens Jasche , Florent Leclercq

We explore the reconstruction of the gravitational lensing field of the cosmic microwave background in real space showing that very little statistical information is lost when estimators of short range on the celestial sphere are used in…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Martin Bucher , Carla Sofia Carvalho , Kavilan Moodley , Mathieu Remazeilles

We theoretically investigate the recovery of global spectrum (monopole) from visibilities (cross-correlation only) measured by the interferometer array and the feasibility of extracting 21 cm signal of cosmic dawn. In our approach, the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Xin Zhang , Bin Yue , Yuan Shi , Fengquan Wu , Xuelei Chen

The inverse problem we consider is to reconstruct the location and shape of buried obstacles in the lower half-space of an unbounded two-layered medium in two dimensions from phaseless far-field data. A main difficulty of this problem is…

Numerical Analysis · Mathematics 2021-05-26 Long Li , Jiansheng Yang , Bo Zhang , Haiwen Zhang

Low-frequency radio observations of neutral hydrogen during and before the epoch of cosmic reionization will provide hundreds of quasi-independent source planes, each of precisely known redshift, if a resolution of ~ 1 arcminutes or better…

Astrophysics · Physics 2010-11-11 R. Benton Metcalf

Direct detection of the Epoch of Reionization via the redshifted 21-cm line will have unprecedented implications on the study of structure formation in the early Universe. To fulfill this promise current and future 21-cm experiments will…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 F. Mertens , A. Ghosh , L. V. E. Koopmans