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We study non-Gaussianity of density perturbations generated by an axionic curvaton, focusing on the case that the curvaton sits near the hilltop of the potential during inflation. Such hilltop curvatons can generate a red-tilted density…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-15 Masahiro Kawasaki , Takeshi Kobayashi , Fuminobu Takahashi

We investigate the relative sensitivities of several tests for deviations from Gaussianity in the primordial distribution of density perturbations. We consider models for non-Gaussianity that mimic that which comes from inflation as well as…

Astrophysics · Physics 2009-10-31 Licia Verde , Raul Jimenez , Marc Kamionkowski , Sabino Matarrese

Clusters of galaxies are the most impressive gravitationally-bound systems in the Universe and its abundance (the cluster mass function) is one important statistics to probe the matter density parameter ($\Omega_m$) and the amplitude of…

Astrophysics · Physics 2014-11-18 L. Marassi , J. V. Cunha , J. A. S. Lima

By assuming the field seeding the curvature perturbations $ \zeta $ is a dynamically arising condensate, we are able to derive the relation $ f_{NL} ^2 \simeq 10^8 H / M_c $ between the non-Gaussianity parameter $ f_{NL} $ and the ratio of…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-25 G. L. Alberghi , R. Casadio

A Cluster Expansion Model (CEM), representing a relativistic extension of Mayer's cluster expansion, is constructed to study baryon number fluctuations in QCD. The temperature dependent first two coefficients, corresponding to the partial…

High Energy Physics - Phenomenology · Physics 2018-07-03 Volodymyr Vovchenko , Jan Steinheimer , Owe Philipsen , Horst Stoecker

Tensor non-Gaussianity represents an important future probe of the physics of inflation. Inspired by recent works, we elaborate further on the possibility of significant primordial tensor non-Gaussianities sourced by extra fields during…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-20 Emanuela Dimastrogiovanni , Matteo Fasiello , Gianmassimo Tasinato , David Wands

The generic prediction for the perturbations generated during slow--roll, single--field inflation, as they appear in the cosmic microwave background (CMB), is a flat, close--to--Gaussian spectrum. We calculate the general solution for a…

Astrophysics · Physics 2007-05-23 S. Gupta

The scalar mode density perturbations in a the warm inflationary scenario are analysed with a view to predicting the amount of non-gaussianity produced by this scenario. The analysis assumes that the inflaton evolution is strongly damped by…

Astrophysics · Physics 2010-10-27 Ian G Moss , Chun Xiong

We obtain concentration estimates for the fluctuations of Coulomb gases in any dimension and in a broad temperature regime, including very small and very large temperature regimes which may depend on the number of points. We obtain a full…

Mathematical Physics · Physics 2022-12-29 Sylvia Serfaty

We analyze the power spectrum and the bispectrum of BOSS galaxy-clustering data using the prediction from the Effective Field Theory of Large-Scale Structure at one-loop order for $\textit{both}$ the power spectrum $\textit{and}$ the…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Guido D'Amico , Matthew Lewandowski , Leonardo Senatore , Pierre Zhang

We carry out N-body simulations of several non-Gaussian structure formation models, including Peebles' isocurvature cold dark matter model, cosmic string models, and a model with primordial voids. We compare the evolution of the cluster…

Astrophysics · Physics 2009-10-31 James Robinson , Jonathan E. Baker

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

We derive cosmological constraints on the matter density, \om, and the amplitude of fluctuations, \sig, using $\mathtt{GalWCat19}$, a catalog of 1800 galaxy clusters we identified in the Sloan Digital Sky Survey-DR13 spectroscopic data set…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 Mohamed H. Abdullah , Anatoly Klypin , Gillian Wilson

We consider curvaton models with potentials that depart slightly from the quadratic form. We show that although such a small departure does not modify significantly the Gaussian part of the curvature perturbation, it can have a pronounced…

Astrophysics · Physics 2008-11-26 Kari Enqvist , Sami Nurmi

We use ensembles of high-resolution CDM simulations to investigate the shape and amplitude of the two point correlation function of rich clusters. The standard scale-invariant CDM model with $\Omega=1$ provides a poor description of the…

Astrophysics · Physics 2015-06-24 R. A. C. Croft , G. Efstathiou

We investigate the impact of non-Gaussian scatter in the cluster mass-observable scaling relation on the mass and redshift distribution of clusters detected by wide area surveys. We parameterize non-Gaussian scatter by incorporating the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Laurie D. Shaw , Gilbert P. Holder , Jonathan Dudley

We explore extensions of hybrid inflationary models in the context of supersymmetric D-term inflation. We point out that a large variety of inflationary scenarios can be encountered when the field content is extended. It is not only…

High Energy Physics - Phenomenology · Physics 2008-11-26 Francis Bernardeau , Tristan Brunier

In the present investigation we use observational data of $ f \sigma_ {8} $ to determine observational constraints in the plane $(\Omega_{m0},\sigma_{8})$ using two different methods: the growth factor parametrization and the numerical…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 A. M. Velásquez-Toribio , Júlio C. Fabris

We investigate primordial non-Gaussianity and dark matter isocurvature fluctuations in the modulated reheating and the curvaton scenarios. In these scenarios, large non-Gaussianity can be generated, on the other hand, depending on how dark…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Tomo Takahashi , Masahide Yamaguchi , Shuichiro Yokoyama

Using cosmological N-body simulations, we study the abundance of local maxima (peaks) and minima (dips) identified in the smoothed distribution of halos and dark matter (DM) on scales of $10-100$s Mpcs. The simulations include Gaussian and…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-08 Adi Nusser , Matteo Biagetti , Vincent Desjacques