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We study the large-scale bias parameter of cosmic voids with primordial non-Gaussian (PNG) initial conditions of the local type. In this scenario, the dark matter halo bias exhibits a characteristic scale dependence on large scales, which…

宇宙学与河外天体物理 · 物理学 2019-07-03 Kwan Chuen Chan , Nico Hamaus , Matteo Biagetti

We present a novel approach to estimate the value of primordial non-Gaussianity ($f_{\rm NL}$) parameter directly from the Cosmic Microwave Background (CMB) maps using a convolutional neural network (CNN). While traditional methods rely on…

宇宙学与河外天体物理 · 物理学 2024-03-26 Chandan G. Nagarajappa , Yin-Zhe Ma

We investigate optimization strategies to measure primordial non-Gaussianity with future spectroscopic surveys. We forecast measurements coming from the 3D galaxy power spectrum and compute constraints on primordial non-Gaussianity…

宇宙学与河外天体物理 · 物理学 2015-08-26 Alvise Raccanelli , Olivier Dore , Neal Dalal

Galaxy bispectrum is a promising probe of inflationary physics in the early universe as a measure of primordial non-Gaussianity (PNG), whereas its signal-to-noise ratio is significantly affected by the mode coupling due to non-linear…

宇宙学与河外天体物理 · 物理学 2021-01-13 Masato Shirasaki , Naonori S. Sugiyama , Ryuichi Takahashi , Francisco-Shu Kitaura

In the neutral hydrogen (HI) intensity mapping (IM) survey, the foreground contamination on the cosmological signals is extremely severe, and the systematic effects caused by radio telescopes themselves further aggravate the difficulties in…

天体物理仪器与方法 · 物理学 2022-07-28 Shulei Ni , Yichao Li , Li-Yang Gao , Xin Zhang

The 21-cm anisotropies from the neutral hydrogen distribution prior to the era of reionization is a sensitive probe of primordial non-Gaussianity. Unlike the case with cosmic microwave background, 21-cm anisotropies provide multi-redshift…

天体物理学 · 物理学 2009-06-23 Asantha Cooray , Chao Li , Alessandro Melchiorri

Primordial non-Gaussianity (PNG) is a signature of fundamental physics in the early universe that is probed by cosmological observations. It is well known that the local type of PNG generates a strong signal in the two-point function of…

宇宙学与河外天体物理 · 物理学 2025-03-28 James M. Sullivan , Uros Seljak

Using $N$-body simulations of cosmological large-scale structure formation, for the first time, we show that the anisotropic primordial non-Gaussianity (PNG) causes a scale-dependent modification, given by $1/k^2$ at small $k$ limit, in the…

宇宙学与河外天体物理 · 物理学 2021-04-21 Kazuyuki Akitsu , Toshiki Kurita , Takahiro Nishimichi , Masahiro Takada , Satoshi Tanaka

Upcoming experiments will map the spatial distribution of the 21-cm signal over three-dimensional volumes of space during the Epoch of Reionization (EoR). Several methods have been proposed to mitigate the issue of astrophysical foreground…

宇宙学与河外天体物理 · 物理学 2024-05-30 Jacob Kennedy , Jonathan Colaço Carr , Samuel Gagnon-Hartman , Adrian Liu , Jordan Mirocha , Yue Cui

(ABRIDGED)The rise of cosmic structure depends upon the statistical distribution of initial density fluctuations generated by inflation. While the simplest models predict an almost perfectly Gaussian distribution, more-general models…

宇宙学与河外天体物理 · 物理学 2015-06-15 Anson D'Aloisio , Jun Zhang , Paul R. Shapiro , Yi Mao

We propose to constrain the primordial (local-type) non-Gaussianity signal by first reconstructing the initial density field to remove the late time non-Gaussianities introduced by gravitational evolution. Our reconstruction algorithm…

宇宙学与河外天体物理 · 物理学 2025-08-21 Xinyi Chen , Nikhil Padmanabhan , Daniel J. Eisenstein

Intensity mapping surveys will provide access to a coarse view of the cosmic large-scale structure in unprecedented large volumes at high redshifts. Given the large fractions of the sky that can be efficiently scanned using emission from…

宇宙学与河外天体物理 · 物理学 2019-01-09 Oliver Leicht , Cora Uhlemann , Francisco Villaescusa-Navarro , Sandrine Codis , Lars Hernquist , Shy Genel

Extracting the neutral hydrogen (HI) signal is a great challenge for cosmological 21cm experiments, both the astrophysical foregrounds and the receiver noise are typically several orders of magnitude greater than the 21cm signal. However,…

宇宙学与河外天体物理 · 物理学 2019-06-14 Qizhi Huang , Fengquan Wu , Reza Ansari , Xuelei Chen

We introduce a general class of models for charaterizing the non-Gaussian properties of foreground contaminants in the cosmic microwave background with view towards the removal of the non-primordial non-Gaussian signal from the primordial…

宇宙学与河外天体物理 · 物理学 2009-11-05 C. S. Carvalho

Next-generation cosmological surveys will probe ever larger volumes of the Universe, including the largest scales, near and beyond the horizon. On these scales, the galaxy power spectrum carries signatures of local primordial…

宇宙学与河外天体物理 · 物理学 2015-10-16 José Fonseca , Stefano Camera , Mário G. Santos , Roy Maartens

We investigate the Wavelet Scattering Transform (WST) as a tool for the study of Primordial non-Gaussianity (PNG) in Large Scale Structure (LSS), and compare its performance with that achievable via a joint analysis with power spectrum and…

宇宙学与河外天体物理 · 物理学 2024-03-27 Matteo Peron , Gabriel Jung , Michele Liguori , Massimo Pietroni

Primordial non-Gaussianity is a sensitive probe of the inflationary era, with a number of important theoretical targets living an order of magnitude beyond the reach of current CMB constraints. Maps of the large-scale structure of the…

宇宙学与河外天体物理 · 物理学 2022-09-07 Daniel Baumann , Daniel Green

We study the effects of astrophysical foregrounds on the ability of CMB B-mode polarization experiments to constrain the primordial tensor-to-scalar ratio, r. To clean the foreground contributions we use parametric, maximum likelihood…

宇宙学与河外天体物理 · 物理学 2012-04-20 Josquin Errard , Radek Stompor

We place new constraints on the primordial local non-Gaussianity parameter f_NL using recent Cosmic Microwave Background anisotropy and galaxy clustering data. We model the galaxy power spectrum according to the halo model, accounting for a…

宇宙学与河外天体物理 · 物理学 2014-11-20 Francesco De Bernardis , Paolo Serra , Asantha Cooray , Alessandro Melchiorri

We study the impact of the cosmological parameters uncertainties on the measurements of primordial non-Gaussianity through the large-scale non-Gaussian halo bias effect. While this is not expected to be an issue for the standard LCDM model,…

宇宙学与河外天体物理 · 物理学 2015-03-13 Carmelita Carbone , Olga Mena , Licia Verde