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We investigate the possibility of constraining primordial non-Gaussianity using the 3D bispectrum of Ly-alpha forest. The strength of the quadratic non-Gaussian correction to an otherwise Gaussian primordial gravitational field is assumed…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-19 Dhiraj Kumar Hazra , Tapomoy Guha Sarkar

We perform a Fisher matrix analysis to forecast the capability of ongoing and future Sunyaev-Zeldovich cluster surveys in constraining the deviations from Gaussian distribution of primordial density perturbations. We use the constraining…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Daisy S. Y. Mak , Elena Pierpaoli

We consider primordial non-Gaussianity due to quadratic corrections in the gravitational potential parametrized by a non-linear coupling parameter fnl. We study constraints on fnl from measurements of the galaxy bispectrum in redshift…

Astrophysics · Physics 2009-11-10 Roman Scoccimarro , Emiliano Sefusatti , Matias Zaldarriaga

We present the results of a set of cosmological N-body simulations with standard $\Lambda$CDM cosmology but characterized by a scale-dependent primordial non-Gaussianity of the local type featuring a power-law dependence of the $f_{\rm…

Inflation, a period of exponential expansion in the early Universe, is considered an important part of the standard $\Lambda$CDM cosmological model, and plays a crucial role in explaining a wide range of current observations. The standard…

General Relativity and Quantum Cosmology · Physics 2023-12-08 Maria Pia Piccirilli , Gabriel Leon

We apply a new method to measure primordial non-Gaussianity, using the cross-correlation between galaxy surveys and the CMB lensing signal to measure galaxy bias on very large scales, where local-type primordial non-Gaussianity predicts a…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-06 Tommaso Giannantonio , Will J. Percival

We investigate the constraints on primordial non-Gaussianity with varied bispectrum shapes that can be derived from the power spectrum of galaxies and clusters of galaxies detected in future wide field optical/near-infrared surveys. Having…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Cosimo Fedeli , Carmelita Carbone , Lauro Moscardini , Andrea Cimatti

We use Bayesian inference and nested sampling to develop a non-parametric method to reconstruct the primordial power spectrum $P_{\mathcal{R}}(k)$ from Large Scale Structure (LSS) data. The performance of the method is studied by applying…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-16 G. Martínez-Somonte , A. Marcos-Caballero , E. Martínez-González , G. Cañas-Herrera

The bispectrum vanishes for linear Gaussian fields and is thus a sensitive probe of non-linearities and non-Gaussianities in the cosmic density field. Hence, a detection of the bispectrum in the halo density field would enable tight…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-18 Tobias Baldauf , Uros Seljak , Leonardo Senatore

Local non-Gaussianity, parametrized by $f_{\rm NL}$, introduces a scale-dependent bias that is strongest at large scales, precisely where General Relativistic (GR) effects also become significant. With future data, it should be possible to…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Marco Bruni , Robert Crittenden , Kazuya Koyama , Roy Maartens , Cyril Pitrou , David Wands

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-11 James M. Sullivan , Shi-Fan Chen

The forthcoming generation of wide-field galaxy surveys will probe larger volumes and galaxy densities, thus allowing for a much larger signal-to-noise ratio for higher-order clustering statistics, in particular the galaxy bispectrum.…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Azadeh Moradinezhad Dizgah , Hayden Lee , Marcel Schmittfull , Cora Dvorkin

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…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-04 Dionysios Karagiannis , Andrei Lazanu , Michele Liguori , Alvise Raccanelli , Nicola Bartolo , Licia Verde

In [1], a most general higher curvature non-local gravity action was derived that admits a particular $R^2$-like inflationary solution predicting the spectral index of primordial scalar perturbations $n_s(N)\approx 1-\frac{2}{N}$, where $N$…

High Energy Physics - Theory · Physics 2023-07-18 Alexey S. Koshelev , K. Sravan Kumar , Alexei A. Starobinsky

We measure the large-scale bias of dark matter halos in simulations with non-Gaussian initial conditions of the local type, and compare this bias to the response of the mass function to a change in the primordial amplitude of fluctuations.…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-16 Matteo Biagetti , Titouan Lazeyras , Tobias Baldauf , Vincent Desjacques , Fabian Schmidt

The primordial non-Gaussianity (PNG) in matter density perturbation is a very powerful probe of the physics of the very early Universe. The local PNG can induce a distinct scale-dependent bias on the large scale structure distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-26 Yan Gong , Xin Wang , Zheng Zheng , Xuelei Chen

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-03 Kwan Chuen Chan , Nico Hamaus , Matteo Biagetti

It has recently been proposed that the large-scale bias of dark matter halos depends sensitively on primordial non-Gaussianity of the local form. In this paper we point out that the strong scale dependence of the non-Gaussian halo bias…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Carlos Cunha , Dragan Huterer , Olivier Dore

Primordial non-Gaussianity generated by additional fields during inflation offers a compelling observational target. Heavy fields imprint characteristic oscillatory signals in non-Gaussian correlation functions of the inflaton, a process…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-13 Daniel Green , Jiashu Han , Benjamin Wallisch

We introduce a non-perturbative method to constrain the amplitude of local-type primordial non-Gaussianity ($f_{\rm NL}$) using squeezed configurations of the CMB lensing convergence and cosmic shear bispectra. First, we use cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-20 Samuel Goldstein , Oliver H. E. Philcox , J. Colin Hill , Angelo Esposito , Lam Hui
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