中文
相关论文

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

200 篇论文

We present the strongest robust constraints on primordial non-Gaussianity (PNG) from currently available galaxy surveys, combining large-scale clustering measurements and their cross-correlations with the cosmic microwave background. We…

Local primordial non-Gaussianity (LPNG) couples long-wavelength cosmological fluctuations to the short-wavelength behavior of galaxies. This coupling is encoded in bias parameters including $b_{\phi}$ and $b_{\delta\phi}$ at linear and…

宇宙学与河外天体物理 · 物理学 2025-02-11 James M. Sullivan , Shi-Fan Chen

Global (i.e. sky-averaged) $21$~cm signal experiments can measure the evolution of the universe from the Cosmic Dawn to the Epoch of Reionization. These measurements are challenged by the presence of bright foreground emission that can be…

宇宙学与河外天体物理 · 物理学 2019-09-25 Marta Spinelli , Gianni Bernardi , Mario G. Santos

Primordial non-Gaussianities (PNGs) are imprints in the initial density field sourced by the dynamics of inflation. These dynamics can induce scale dependence, oscillations, and other features in the primordial bispectrum. We analyze a…

宇宙学与河外天体物理 · 物理学 2026-03-24 Dhayaa Anbajagane , Hayden Lee

The primordial non-Gaussianity induces scale-dependent bias of the \hi with respect to the underlying dark matter, which exhibits features on the very large scales of the 21-cm power spectrum potentially observable with \hi intensity…

宇宙学与河外天体物理 · 物理学 2017-10-04 Yi-Chao Li , Yin-Zhe Ma

Current and upcoming 21-cm experiments will soon be able to map 21-cm spatial fluctuations in three dimensions for a wide range of redshifts. However, bright foreground contamination and the nature of radio interferometry create significant…

宇宙学与河外天体物理 · 物理学 2025-12-01 Shu-Fan Chen , Kai-Feng Chen , Cora Dvorkin

We provide perturbation theory predictions for the HI intensity mapping power spectrum multipoles using the Effective Field Theory of Large Scale Structure (EFTofLSS), which should allow us to constrain cosmological parameters exploiting…

宇宙学与河外天体物理 · 物理学 2023-02-02 Alkistis Pourtsidou

We forecast constraints on primordial non-Gaussianity (PNG) and bias parameters from measurements of galaxy power spectrum and bispectrum in future radio continuum and optical surveys. In the galaxy bispectrum, we consider a comprehensive…

宇宙学与河外天体物理 · 物理学 2018-05-04 Dionysios Karagiannis , Andrei Lazanu , Michele Liguori , Alvise Raccanelli , Nicola Bartolo , Licia Verde

Measurement of the global 21-cm signal during Cosmic Dawn (CD) and the Epoch of Reionization (EoR) is made difficult by bright foreground emission which is 2-5 orders of magnitude larger than the expected signal. Fitting for a…

宇宙学与河外天体物理 · 物理学 2024-02-20 Michael Pagano , Peter Sims , Adrian Liu , Dominic Anstey , Will Handley , Eloy De Lera Acedo

Primordial non-Gaussianities (PNGs) are signatures in the density field that encode particle physics processes from the inflationary epoch. Such signatures have been extensively studied using the Cosmic Microwave Background, through…

宇宙学与河外天体物理 · 物理学 2024-04-01 Dhayaa Anbajagane , Chihway Chang , Hayden Lee , Marco Gatti

The precise measurement of the sky-averaged HI absorption signal between 50 and 200 MHz is the primary goal of global 21-cm cosmology. This measurement has the potential to unravel the underlying physics of cosmic structure formation and…

宇宙学与河外天体物理 · 物理学 2024-12-04 Emma Shen , Dominic Anstey , Marta Spinelli , Eloy de Lera Acedo , Anastasia Fialkov

Our view of the last-scattering surface in the cosmic microwave background (CMB) is obscured by secondary anisotropies, sourced by scattering, extragalactic emission and gravitational processes between recombination and observation. Whilst…

宇宙学与河外天体物理 · 物理学 2023-05-10 William Coulton , Alexander Miranthis , Anthony Challinor

Aiming to correctly restore the redshifted 21 cm signals emitted by the neutral hydrogen during the cosmic reionization processes, we re-examine the separation approaches based on the quadratic polynomial fitting technique in frequency…

宇宙学与河外天体物理 · 物理学 2015-06-12 Jingying Wang , Haiguang Xu , Tao An , Junhua Gu , Xueying Guo , Weitian Li , Yu Wang , Chengze Liu , Olivier Martineau-Huynh , Xiang-Ping Wu

We analyse the large-scale angular clustering of quasars in the \gaia-\unwise quasar catalog, \quaia, and their cross-correlation with maps of the lensing convergence of the Cosmic Microwave Background (CMB), to constrain the level of…

宇宙学与河外天体物理 · 物理学 2026-05-19 Giulio Fabbian , David Alonso , Kate Storey-Fisher , Thomas Cornish

Neutral hydrogen (HI) intensity mapping with single-dish experiments is a powerful approach for probing cosmology in the post-reionization epoch. However, the presence of bright foregrounds over four orders of magnitude stronger than the HI…

宇宙学与河外天体物理 · 物理学 2026-02-03 Athanasia Gkogkou , Victor Bonjean , Jean-Luc Starck , Marta Spinelli , Panagiotis Tsakalides

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…

天体物理学 · 物理学 2009-10-07 Max Tegmark , Daniel J. Eisenstein , Wayne Hu , Angelica de Oliveira-Costa

Constraining primordial non-Gaussianities (PNGs) in the large-scale cosmic structure (LSS) is an important step in understanding properties of the early universe, specifically in distinguishing between different inflationary models.…

宇宙学与河外天体物理 · 物理学 2026-01-14 Ethan Vislosky , Zachery Brown , Regina Demina , Edmond Chaussidon

[Abridged.] It is conceivable that no single statistical estimator can be sensitive to all forms and levels of non-Gaussianity that may be present in observed CMB data. In recent works a statistical procedure based upon the calculation of…

宇宙学与河外天体物理 · 物理学 2015-01-14 A. Bernui , M. J. Reboucas

We study Minkowski Functionals as probes of primordial non-Gaussianity in the Cosmic Microwave Background, specifically for the estimate of the primordial `local' bi-spectrum parameter f_NL, with instrumental parameters which should be…

宇宙学与河外天体物理 · 物理学 2015-06-11 Anne Ducout , François Bouchet , Stéphane Colombi , Dmitri Pogosyan , Simon Prunet

21-cm intensity mapping (IM) is a powerful technique to probe the large-scale distribution of neutral hydrogen (HI) and extract cosmological information such as the baryon acoustic oscillation feature. A key challenge lies in recovering the…

宇宙学与河外天体物理 · 物理学 2025-11-24 Zitong Wang , Feng Shi , Le Zhang , Yanming Liu , Xiaoping Li , Shulei Ni , Ming Jiang , Xiaofan Ma