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相关论文: Constraining equilateral-type primordial non-Gauss…

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We present constraints on $f_{\rm NL}$, the parameter quantifying the amplitude of local Primordial Non-Gaussianities (PNG), from a combined analysis of the tree-level power spectrum and bispectrum of Data Release $16$ (DR16) of the…

宇宙学与河外天体物理 · 物理学 2025-07-21 Marina S. Cagliari , Matilde Barberi-Squarotti , Kevin Pardede , Emanuele Castorina , Guido D'Amico

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 the implementation of a fast estimator for the full dark matter bispectrum of a three-dimensional particle distribution relying on a separable modal expansion of the bispectrum. The computational cost of accurate bispectrum…

宇宙学与河外天体物理 · 物理学 2014-02-04 M. M. Schmittfull , D. M. Regan , E. P. S. Shellard

We computed the power spectrum of weak cosmic shear in models with non-Gaussian primordial density fluctuations. Cosmological initial conditions deviating from Gaussianity have recently attracted much attention in the literature, especially…

宇宙学与河外天体物理 · 物理学 2015-05-14 C. Fedeli , L. Moscardini

We investigate the possibility of using future photometric and radio surveys to constrain the power spectrum of primordial fluctuations that is predicted by inflationary models with a violation of the slow-roll phase. We forecast…

宇宙学与河外天体物理 · 物理学 2018-04-17 Mario Ballardini , Fabio Finelli , Roy Maartens , Lauro Moscardini

Focusing on the local type primordial non-Gaussianities, we study the bispectrum and trispectrum during a non-minimal slow-roll inflation. We use the so-called $\delta N$ formalism to investigate the super-horizon evolution of the…

宇宙学与河外天体物理 · 物理学 2018-08-28 Kosar Asadi , Kourosh Nozari

Long-short mode coupling during inflation, encoded in the squeezed bispectrum of curvature perturbations, induces a dependence of the local, small-scale power spectrum on long-wavelength perturbations, leading to a scale-dependent halo…

宇宙学与河外天体物理 · 物理学 2018-09-19 Giovanni Cabass , Enrico Pajer , Fabian Schmidt

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

High-precision constraints on primordial non-Gaussianity (PNG) will significantly improve our understanding of the physics of the early universe. Among all the subtleties in using large scale structure observables to constrain PNG,…

宇宙学与河外天体物理 · 物理学 2017-03-10 E. Di Dio , H. Perrier , R. Durrer , G. Marozzi , A. Moradinezhad Dizgah , J. Noreña , A. Riotto

Modeling the nonlinearity of the halo bispectrum remains a major challenge in modern cosmology, in particular for ongoing and upcoming large-scale structure observations that are performed to study the inflationary physics. The "power…

宇宙学与河外天体物理 · 物理学 2017-06-21 Chi-Ting Chiang

In single-field inflationary models with a low sound speed, the orthogonal shape of the primordial bispectrum arises due to partial cancellations between equilateral-type shapes. This fact allows for a speed of sound c_s as low as about…

宇宙学与河外天体物理 · 物理学 2015-06-15 Sebastien Renaux-Petel

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

A convincing detection of primordial non-Gaussianity in the local form of the bispectrum, whose amplitude is given by the fNL parameter, offers a powerful test of inflation. In this paper we calculate the modification of two-point…

宇宙学与河外天体物理 · 物理学 2014-11-20 Donghui Jeong , Eiichiro Komatsu , Bhuvnesh Jain

We derive analytical formulae for the Minkowski Functions of the cosmic microwave background (CMB) and large-scale structure (LSS) from primordial non-Gaussianity. These formulae enable us to estimate a non-linear coupling parameter, f_NL,…

天体物理学 · 物理学 2011-02-11 Chiaki Hikage , Eiichiro Komatsu , Takahiko Matsubara

We investigate whether a Gaussian likelihood, as routinely assumed in the analysis of cosmological data, is supported by simulated survey data. We define test statistics, based on a novel method that first destroys Gaussian correlations in…

宇宙学与河外天体物理 · 物理学 2017-11-15 Elena Sellentin , Alan F. Heavens

We present a new method to constrain local primordial non-Gaussianity using the large-scale modulation of the local lensing power spectrum. Our work extends our recently proposed $\pi$-field method for primordial non-Gaussianity estimation…

宇宙学与河外天体物理 · 物理学 2026-05-06 Shi-Hui Zang , Moritz Münchmeyer

Two of the most commonly used tools to constrain the primordial non-Gaussianity are the bispectrum and the Minkowski functionals of CMB temperature anisotropies. These two measures of non-Gaussianity in principle provide distinct (though…

宇宙学与河外天体物理 · 物理学 2015-03-26 Wenjuan Fang , Adam Becker , Dragan Huterer , Eugene A. Lim

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

The Planck CMB experiment has delivered the best constraints so far on primordial non-Gaussianity, ruling out early-Universe models of inflation that generate large non-Gaussianity. Although small improvements in the CMB constraints are…

Measuring the small primordial nonGaussianity (PNG) predicted by cosmic inflation theories may help diagnose them. The detectability of PNG by its imprint on the 21cm power spectrum from the epoch of reionization is reassessed here in terms…

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