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We study how primordial non-Gaussianities affect the clustering of voids at large scales. We derive a formula of the bias of voids induced from the non-Gaussianities by making use of the functional integral method. In a similar way as of…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-02 Toyokazu Sekiguchi , Shuichiro Yokoyama

When dealing with observables, one needs to generalize the bias relation between the observed galaxy fluctuation field to the underlying matter distribution in a gauge-invariant way. We provide such relation at second-order in perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-20 N. Bartolo , S. Matarrese , A. Riotto

We show how the excursion set moving barrier model for halo abundances may be generalized to the local non-Gaussian f_{nl} model. Our estimate assumes that the distribution of step sizes depends on f_{nl}, but that they are otherwise…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Tsz Yan Lam , Ravi K. Sheth

Primordial non-Gaussianity of local type is known to produce a scale-dependent contribution to the galaxy bias. Several classes of multi-field inflationary models predict non-Gaussian bias which is stochastic, in the sense that dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-05 Simone Ferraro , Kendrick M. Smith

The presence of additional particles during inflation leads to non-Gaussianity in late-time correlators of primordial curvature perturbations. The shape and amplitude of this signal depend on the mass and spin of the extra particles.…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-16 Azadeh Moradinezhad Dizgah , Cora Dvorkin

We present N-body simulations for generic non-Gaussian initial conditions with the aim of exploring and modelling the scale-dependent halo bias. This effect is evident at very large scales requiring large simulation boxes. In addition, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Christian Wagner , Licia Verde

Primordial non-Gaussianity can lead to a scale-dependent bias in the density of collapsed halos relative to the underlying matter density. The galaxy power spectrum already provides constraints on local-type primordial non-Gaussianity…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-15 Matteo Tellarini , Ashley J. Ross , Gianmassimo Tasinato , David Wands

Recently multi-field inflation models that can produce large scalar fluctuations on small scales have drawn a lot of attention, primarily because they could lead to primordial black hole production and generation of large second-order…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-21 Laura Iacconi , David J. Mulryne

We compute the matter bispectrum in the presence of primordial local non-Gaussianity over a wide range of scales, including the very small nonlinear ones. We use the Halo Model approach, considering non-Gaussian corrections to the halo…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 D. G. Figueroa , E. Sefusatti , A. Riotto , F. Vernizzi

We investigate the halo bias in the case where the primordial curvature fluctuations, $\Phi$, are sourced from both a Gaussian random field and a Gaussian-squared field, as $\Phi({\bf x}) = \phi({\bf x}) + \psi({\bf x})^2 - <\psi({\bf…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Shuichiro Yokoyama

We discuss how primordial non-Gaussianity of the curvature perturbation helps to constrain models of the early universe. Observations are consistent with Gaussian initial conditions, compatible with the predictions of the simplest models of…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-26 Christian T. Byrnes

DHOST inflation models where deviations from a pure de Sitter background are induced by an axion-like potential can lead to large non-Gaussianities. We investigate the nature of non-Gaussianities in these models and compare to the results…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-31 Philippe Brax , Andrei Lazanu

Corrections induced by primordial non-Gaussianity to the linear halo bias can be computed from a peak-background split or the widespread local bias model. However, numerical simulations clearly support the prediction of the former, in which…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Vincent Desjacques , Jinn-Ouk Gong , Antonio Riotto

We derive approximated, yet very accurate analytical expressions for the abundance and clustering properties of dark matter halos in the excursion set peak framework; the latter relies on the standard excursion set approach, but also…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 A. Lapi , L. Danese

We present a method, based on the correlation function of excursion sets above a given threshold, to test the Gaussianity of the CMB temperature fluctuations in the sky. In particular, this method can be applied to discriminate between…

Astrophysics · Physics 2009-10-30 R. B. Barreiro , J. L. Sanz , E. Martinez-Gonzalez , J. Silk

We give an analytical form for the weighted correlation function of peaks in a Gaussian random field. In a cosmological context, this approach strictly describes the formation bias and is the main result here. Nevertheless, we show its…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-24 Licia Verde , Raul Jimenez , Fergus Simpson , Luis Alvarez-Gaume , Alan Heavens , Sabino Matarrese

Recent results of N-body simulations have shown that current theoretical models are not able to correctly predict the amplitude of the scale-dependent halo bias induced by primordial non-Gaussianity, for models going beyond the simplest,…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Vincent Desjacques , Donghui Jeong , Fabian Schmidt

The physics of primordial black holes can be affected by the non-Gaussian statistics of the density fluctuations that generate them. Therefore, it is important to have good theoretical control of the higher-order correlation functions for…

High Energy Physics - Theory · Physics 2024-04-16 Gianmassimo Tasinato

We study a particular Galileon inflation in the light of Planck2015 observational data in order to constraint the model parameter space. We study the spectrum of the primordial modes of the density perturbations by expanding the action up…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Kosar Asadi , Kourosh Nozari

We study structure formation in the presence of primordial non-Gaussianity of the local type with parameters f_NL and g_NL. We show that the distribution of dark-matter halos is naturally described by a multivariate bias scheme where the…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-14 Tommaso Giannantonio , Cristiano Porciani