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Related papers: Non-Gaussianity and Excursion Set Theory: Halo Bia…

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Correlated adiabatic and isocurvature perturbation modes are produced during inflation through an oscillation mechanism when extra scalar degrees of freedom other than the inflaton field are present. We show that this correlation…

High Energy Physics - Phenomenology · Physics 2009-11-07 N. Bartolo , S. Matarrese , A. Riotto

We compute analytic expressions for the non-linearity parameters characterizing the bi- and tri-spectrum of primordial curvature perturbations generated during an inflationary epoch of the early universe driven by an arbitrary number of…

High Energy Physics - Theory · Physics 2011-11-04 Diana Battefeld , Thorsten Battefeld

We investigate the non-Gaussianities of inflation driven by a single scalar field coupling non-minimally to the Einstein Gravity. We assume that the form of the scalar field is very general with an arbitrary sound speed. For convenience to…

High Energy Physics - Theory · Physics 2011-05-27 Taotao Qiu , Kwei-Chou Yang

We compute non-Gaussianities in N-flation, a string motivated model of assisted inflation with quadratic, separable potentials and masses given by the Marcenko-Pastur distribution. After estimating parameters characterizing the bi- and…

High Energy Physics - Theory · Physics 2010-10-27 Diana Battefeld , Thorsten Battefeld

We apply the integrated perturbation theory (Matsubara 2011, PRD 83, 083518) to evaluate the scale-dependent bias in the presence of primordial non-Gaussianity. The integrated perturbation theory is a general framework of nonlinear…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Takahiko Matsubara

The theory and methodology is developed to compute the bispectrum in warm inflation, leading to results for the non-linearity parameter and the shape of the bispectrum. Particular attention is paid to the study of the bispectrum in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Mar Bastero-Gil , Arjun Berera , Ian G. Moss , Rudnei O. Ramos

We provide a simple formula that accurately approximates the first crossing distribution of barriers having a wide variety of shapes, by random walks with a wide range of correlations between steps. Special cases of it are useful for…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-25 Marcello Musso , Ravi K. Sheth

Primordial gravitational waves (PGWs) generate scalar density perturbations at second order. Since the induced density contrast is quadratic in the tensor field, it is intrinsically non-Gaussian. We study the imprint of this tensor-induced…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Mariam Abdelaziz , Pritha Bari , Sabino Matarrese , Angelo Ricciardone

Primordial non-Gaussianity of the local type induces a strong scale-dependent bias on the clustering of halos in the late-time Universe. This signature is particularly promising to provide constraints on the non-Gaussianity parameter…

If cosmic inflation suffered tiny time-dependent deviations from the slow-roll regime, these would induce the existence of small scale-dependent features imprinted in the primordial spectra, with their shapes and sizes revealing information…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Sander Mooij , Gonzalo A. Palma , Grigoris Panotopoulos , Alex Soto

The strong dependence of the large-scale dark matter halo bias on the (local) non-Gaussianity parameter, f_NL, offers a promising avenue towards constraining primordial non-Gaussianity with large-scale structure surveys. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-14 Beth A. Reid , Licia Verde , Klaus Dolag , Sabino Matarrese , Lauro Moscardini

Halos are biased tracers of the dark matter distribution. It is often assumed that the patches from which halos formed are locally biased with respect to the initial fluctuation field, meaning that the halo-patch fluctuation field can be…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-08 Ravi K. Sheth , Kwan Chuen Chan , Roman Scoccimarro

We describe how to extend the excursion set peaks framework so that its predictions of dark halo abundances and clustering can be compared directly with simulations. These extensions include: a halo mass definition which uses the TopHat…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Aseem Paranjape , Ravi K. Sheth , Vincent Desjacques

The abundance of collapsed objects in the universe, or halo mass function, is an important theoretical tool in studying the effects of primordially generated non-Gaussianities on the large scale structure. The non-Gaussian mass function has…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Guido D'Amico , Marcello Musso , Jorge Noreña , Aseem Paranjape

While large scale primordial non-Gaussianity is strongly constrained by present-day data, there are no such constraints at Mpc scales. Here we investigate the effect of significant small-scale primordial non-Gaussianity on structure…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Clément Stahl , Thomas Montandon , Benoit Famaey , Oliver Hahn , Rodrigo Ibata

The Press-Schechter (PS) and excursion set (ES) models of structure formation fail in reproducing the halo bias found in simulations, while the excursion set-peaks (ESP) formalism built in the peak model reproduces it only at high masses…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-07 Eduard Salvador-Solé , Alberto Manrique

We discuss generation of non-Gaussianity in density perturbation through the super-horizon evolution during inflation by using the so-called $\delta N$ formalism. We first provide a general formula for the non-linearity parameter generated…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Takahiro Tanaka , Teruaki Suyama , Shuichiro Yokoyama

In this paper we calculate additional contributions to that part of the non-Gaussianity of the curvature perturbation, which come from the three-point correlator of the field perturbations. We estimate this contribution in the following…

Astrophysics · Physics 2007-05-23 Ignacio Zaballa , Yeinzon Rodriguez , David H. Lyth

The excursion set model provides a convenient theoretical framework to derive dark matter halo abundances. This paper generalizes the model by introducing a more realistic merging and collapse process. A new parameter regulates the…

Astrophysics · Physics 2009-11-10 Grigori Amosov , Peter Schuecker

We extend the formalism to calculate non-Gaussianity of primordial curvature perturbations produced by preheating in the presence of a light scalar field. The calculation is carried out in the separate universe approximation using the…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-31 Pulkit S. Ghoderao , Arttu Rajantie
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