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Related papers: Low multipole mapmaking for global 21-cm experimen…

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Large Scale Structures (LSS) in the universe can be traced using the neutral atomic hydrogen HI through its 21cm emission. Such a 3D matter distribution map can be used to test the Cosmological model and to constrain the Dark Energy…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 R. Ansari , J. E. Campagne , P. Colom , J. M. Le Goff , C. Magneville , J. M. Martin , M. Moniez , J. Rich , C. Yèche

The natural approach to a spectral analysis of data distributed on the sky employs spherical harmonic decomposition. A common problem encountered in practical astronomy is the lack of full sky coverage in the available data. For example,…

Astrophysics · Physics 2009-10-22 Krzysztof M. Gorski

The HI 21cm global signal from the Cosmic Dawn and the Epoch of Reionization (EoR) offers critical insights into the evolution of our Universe. Yet, its detection presents significant challenges due to its extremely low…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-09 Yue Wang , Xin Wang , Shijie Sun , Fengquan Wu , Shoudong Luo , Xuelei Chen

The Mapper of the IGM Spin Temperature (MIST) is a new ground-based, single-antenna, radio experiment attempting to detect the global 21 cm signal from the Dark Ages and Cosmic Dawn. A significant challenge in this measurement is the…

We present a new blind formulation of the Cosmic Microwave Background (CMB) inference problem. The approach relies on a phenomenological model of the multi-frequency microwave sky without the need for physical models of the individual…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-30 Flavien Vansyngel , Benjamin D. Wandelt , Jean-François Cardoso , Karim Benabed

One of the main challenges facing upcoming CMB experiments will be to distinguish the cosmological signal from foreground contamination. We present a comprehensive treatment of this problem and study how foregrounds degrade the accuracy…

Astrophysics · Physics 2009-10-07 Max Tegmark , Daniel J. Eisenstein , Wayne Hu , Angelica de Oliveira-Costa

The presence of astrophysical emissions in microwave observations forces us to perform component separation to extract the Cosmic Microwave Background (CMB) signal. However, even in the most optimistic cases, there are still strongly…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-26 C. Gimeno-Amo , E. Martínez-González , R. B. Barreiro

The reliable detection of the global 21-cm signal, a key tracer of Cosmic Dawn and the Epoch of Reionization, requires meticulous data modelling and robust statistical frameworks for model validation and comparison. In Paper I of this…

We question the global universe isotropy by probing the alignment of local structures in the cosmic microwave background (CMB) radiation. The original method proposed relies on a steerable wavelet decomposition of the CMB signal on the…

Astrophysics · Physics 2007-05-23 Y. Wiaux , P. Vielva , E. Martinez-Gonzalez , P. Vandergheynst

Detection of redshifted \ion{H}{i} 21-cm emission is a potential probe for investigating the Universe's first billion years. However, given the significantly brighter foreground, detecting 21-cm is observationally difficult. The Earth's…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-30 Anshuman Tripathi , Abhirup Datta , Madhurima Choudhury , Suman Majumdar

The study of the magnification bias produced on high-redshift sub-millimetre galaxies by foreground galaxies through the analysis of the cross-correlation function was recently demonstrated as an interesting independent alternative to the…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 J. Gonzalez-Nuevo , M. M. Cueli , L. Bonavera , A. Lapi , M. Migliaccio , F. Argüeso , L. Toffolatti

The large-angle, low multipole cosmic microwave background (CMB) provides a unique view of the largest angular scales in the Universe. Study of these scales is hampered by the facts that we have only one Universe to observe, only a few…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Craig J. Copi , Dragan Huterer , Dominik J. Schwarz , Glenn D. Starkman

In the first paper of this series, we proposed a novel method to probe large-scale intergalactic magnetic fields during the cosmic Dark Ages, using 21-cm tomography. This method relies on the effect of spin alignment of hydrogen atoms in a…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-26 Vera Gluscevic , Tejaswi Venumadhav , Xiao Fang , Christopher Hirata , Antonija Oklopcic , Abhilash Mishra

In this chapter, the use of machine learning (ML) in redshifted 21 cm cosmology is discussed, especially for the cosmic dawn, the Epoch of Reionization, and the scientific program of SKA-Low. The 21 cm signal is useful because it can…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-18 Hayato Shimabukuro

We use a simple model to investigate the effect of polarized Galactic foreground emission on the ability of planned CMB missions to detect and model CMB polarization. Emission from likely polarized sources (synchrotron and spinning dust)…

Astrophysics · Physics 2007-05-23 A. Kogut , G. Hinshaw

We present a new method that simultaneously solves for cosmology and galaxy bias on non-linear scales. The method uses the halo model to analytically describe the (non-linear) matter distribution, and the conditional luminosity function…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Frank van den Bosch , Surhud More , Marcello Cacciato , Houjun Mo , Xiaohu Yang

We propose a new internal linear combination (ILC) method in the pixel space, applicable on large angular scales of the sky, to estimate a foreground minimized Cosmic Microwave Background (CMB) temperature anisotropy map by incorporating…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Vipin Sudevan , Rajib Saha

Cosmological simulations suggest that most of the matter in the Universe is distributed along filaments connecting galaxies. Illuminated by the cosmic UV background (UVB), these structures are expected to glow in fluorescent Lyman alpha…

Extracting information from cosmic surveys is often done in a two-step process, construction of maps and then summary statistics such as two-point functions. We use simulations to demonstrate the advantages of a general Bayesian framework…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-06 Alan Junzhe Zhou , Scott Dodelson

We present a new approach to component separation in multifrequency CMB experiments by formulating the problem as that of partitioning the sky into pixel clusters such that within each pixel cluster the foregrounds have similar spectrum,…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-18 Rishi Khatri