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相关论文: The degeneracy between primordial non-Gaussianity …

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Observations of the EoR with the 21-cm hyperfine emission of neutral hydrogen (HI) promise to open an entirely new window onto the formation of the first stars, galaxies and accreting black holes. In order to characterize the weak 21-cm…

宇宙学与河外天体物理 · 物理学 2015-08-06 Abhik Ghosh , L. V. E. Koopmans , Emma Chapman , Vibor Jelic

While usually cosmological initial conditions are assumed to be Gaussian, inflationary theories can predict a certain amount of primordial non-Gaussianity which can have an impact on the statistical properties of the lensing observables. In…

宇宙学与河外天体物理 · 物理学 2015-03-17 F. Pace , L. Moscardini , M. Bartelmann , E. Branchini , K. Dolag , M. Grossi , S. Matarrese

Intensity mapping of the HI 21 cm line and the CO 2.61 mm line from the epoch of reionization has emerged as powerful, complementary, probes of the high-redshift Universe. However, both maps and their cross-correlation are dominated by…

宇宙学与河外天体物理 · 物理学 2021-01-11 Meng Zhou , Jianrong Tan , Yi Mao

Active Galactic Nuclei (AGN) and star-forming galaxies are leading candidates for being the luminous sources that reionized our Universe. Next-generation 21cm surveys are promising to break degeneracies between a broad range of reionization…

宇宙学与河外天体物理 · 物理学 2018-12-20 Sultan Hassan , Adrian Liu , Saul Kohn , Paul La Plante

Detecting and characterizing the Epoch of Reionization and Cosmic Dawn via the redshifted 21-cm hyperfine line of neutral hydrogen will revolutionize the study of the formation of the first stars, galaxies, black holes and intergalactic gas…

宇宙学与河外天体物理 · 物理学 2018-05-23 F. G. Mertens , A. Ghosh , L. V. E. Koopmans

One of the critical challenges facing imaging studies of the 21-cm signal at the Epoch of Reionization (EoR) is the separation of astrophysical foreground contamination. These foregrounds are known to lie in a wedge-shaped region of…

宇宙学与河外天体物理 · 物理学 2024-02-27 Samuel Gagnon-Hartman , Yue Cui , Jacob Kennedy , Adrian Liu , Siamak Ravanbakhsh

Understanding large-angular-scale galactic foregrounds is crucial for future CMB experiments aiming to detect $B$-mode polarization from primordial gravitational waves. Traditionally, the dust component has been separated using its…

宇宙学与河外天体物理 · 物理学 2019-12-18 Guangyu Zhang , Chi-Ting Chiang , Chris Sheehy , Anže Slosar , Jian Wang

This paper provides full sky maps of foreground emission in all WMAP channels, with very low residual contamination from the Cosmic Microwave Background (CMB) anisotropies and controlled level of instrumental noise. Foreground maps are…

宇宙学与河外天体物理 · 物理学 2013-09-25 Tuhin Ghosh , Jacques Delabrouille , Mathieu Remazeilles , Jean-Francois Cardoso , Tarun Souradeep

We report the test results of several independent foreground-cleaning pipelines used in the Ali CMB Polarization Telescope experiment (AliCPT-1), a high-altitude CMB imager in the Northern hemisphere with thousands of detectors dedicated to…

The next generation of CMB experiments should get a better handle on cosmological parameters by mapping the weak lensing deflection field, which is separable from primary anisotropies thanks to the non-Gaussianity induced by lensing.…

天体物理学 · 物理学 2009-11-10 Julien Lesgourgues , Michele Liguori , Sabino Matarrese , Antonio Riotto

After reionisation, the 21cm emission line of neutral hydrogen within galaxies provides a tracer of dark matter. Next-generation intensity mapping surveys, with the SKA and other radio telescopes, will cover large sky areas and a wide range…

宇宙学与河外天体物理 · 物理学 2022-02-07 Dionysios Karagiannis , José Fonseca , Roy Maartens , Stefano Camera

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…

宇宙学与河外天体物理 · 物理学 2011-09-30 Shahab Joudaki , Olivier Dore , Luis Ferramacho , Manoj Kaplinghat , Mario G. Santos

The removal of the Galactic and extragalactic foregrounds remains a major challenge for those wishing to make a detection of the Epoch of Reionization 21-cm signal. Multiple methods of modelling these foregrounds with varying levels of…

宇宙学与河外天体物理 · 物理学 2016-09-13 Emma Chapman , Saleem Zaroubi , Filipe Abdalla , Fred Dulwich , Vibor Jelić , Benjamin Mort

The upcoming Square Kilometre Array Observatory (SKAO) will produce images of neutral hydrogen distribution during the epoch of reionization by observing the corresponding 21-cm signal. However, the 21-cm signal will be subject to…

Primordial non-Gaussianity (PNG) in Large Scale Structures is obfuscated by the many additional sources of non-linearity. Within the Effective Field Theory approach to Standard Perturbation Theory, we show that matter non-linearities in the…

宇宙学与河外天体物理 · 物理学 2016-08-31 Yvette Welling , Drian van der Woude , Enrico Pajer

In 21cm intensity mapping of the large-scale structure (LSS), regions in Fourier space could be compromised by foreground contamination. In interferometric observations, this contamination, known as the foreground wedge, is exacerbated by…

宇宙学与河外天体物理 · 物理学 2025-03-27 Qian Li , Xin Wang , Xiaodong Li , Jiacheng Ding , Tiancheng Luan , Xiaolin Luo

The long wavelength modes lost to bright foregrounds in the interferometric 21-cm surveys can partially be recovered using a forward modeling approach that exploits the non-linear coupling between small and large scales induced by…

宇宙学与河外天体物理 · 物理学 2021-10-27 Chirag Modi , Martin White , Emanuele Castorina , Anže Slosar

Non-gaussianity in the initial conditions of the universe is one of the most powerful mechanisms to discriminate among the competing theories of the early universe. Measurements using bispectrum of cosmic microwave background anisotropies…

天体物理学 · 物理学 2009-02-23 Uros Seljak

The detection of Cosmic Microwave Background primordial $B$-mode polarization would constitute a ``smoking gun" signal of primordial gravitational waves. However, this measurement requires accurate removal of polarized Galactic foregrounds…

宇宙学与河外天体物理 · 物理学 2026-03-18 Luca Gomez Bachar , Cora Dvorkin , Alberto Daniel Supanitsky