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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

We present a class of models in which the primordial metric fluctuations do not necessarily obey Gaussian statistics. These models are realizations of mechanisms in which non-Gaussianity is first generated by a light scalar field and then…

Astrophysics · Physics 2009-11-11 Francis Bernardeau , Tristan Brunier , Jean-Philippe Uzan

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

Cosmic inflation provides a mechanism for generating the early density perturbations that seeded the large-scale structures we see today. Primordial non-Gaussianity is among the most promising of few observational tests of physics at this…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-10 Marilena LoVerde , Simone Ferraro , Kendrick M. Smith

We use the statistics of regions above or below a temperature threshold (excursion sets) to study the cosmic microwave background (CMB) anisotropy in models with primordial non-Gaussianity of the local type. By computing the full-sky…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Graziano Rossi , Pravabati Chingangbam , Changbom Park

Primordial, non-Gaussian perturbations can generate scale-dependent bias in the galaxy distribution. This in turn will modify correlations between galaxy positions and peculiar velocities at late times, since peculiar velocities reflect the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Yin-Zhe Ma , James E. Taylor , Douglas Scott

We provide a dynamical mechanism to generate localized features during inflation. The local feature is due to a sharp waterfall phase transition which is coupled to the inflaton field. The key effect is the contributions of waterfall…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Ali Akbar Abolhasani , Hassan Firouzjahi , Shahram Khosravi , Misao Sasaki

Following the discovery of the CMB, the hot big-bang model has become the standard cosmological model. In this theory, small primordial fluctuations are subsequently amplified by gravity to form the large-scale structure seen today.…

Astrophysics · Physics 2015-06-24 Licia Verde

Gravity is a non-linear theory, and hence, barring cancellations, the initial super-horizon perturbations produced by inflation must contain some minimum amount of mode coupling, or primordial non-Gaussianity. In single-field slow-roll…

High Energy Physics - Theory · Physics 2017-01-11 Giovanni Cabass , Enrico Pajer , Fabian Schmidt

We study non-Gaussianity, the spectral index of primordial scalar fluctuations and tensor modes in models where fluctuations from the inflaton and the curvaton can both contribute to the present cosmic density fluctuations. Even though…

Astrophysics · Physics 2008-11-26 Kazuhide Ichikawa , Teruaki Suyama , Tomo Takahashi , Masahide Yamaguchi

Primordial non-Gaussianity encodes valuable information about the physics of inflation, including the spectrum of particles and interactions. Significant improvements in our understanding of non-Gaussanity beyond Planck require information…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Jérôme Gleyzes , Roland de Putter , Daniel Green , Olivier Doré

We study the impact of the cosmological parameters uncertainties on the measurements of primordial non-Gaussianity through the large-scale non-Gaussian halo bias effect. While this is not expected to be an issue for the standard LCDM model,…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Carmelita Carbone , Olga Mena , Licia Verde

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…

We test the consistency of estimates of the non-linear coupling constant f_{NL} using non-Gaussian CMB maps generated by the method described in (Liguori, Matarrese and Moscardini 2003). This procedure to obtain non-Gaussian maps differs…

Astrophysics · Physics 2009-11-10 P. Cabella , M. Liguori , F. K. Hansen , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

The subject of this paper is the investigation of inflationary non-Gaussianities of the local type with extreme value statistics of the weak lensing convergence kappa. Specifically, we describe the influence of inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-08 Federica Capranico , Angelos Fotios Kalovidouris , Bjoern Malte Schaefer

We investigate the statistical power of higher-order statistics and cross-correlation statistics to constrain the primordial non-Gaussianity from the imaging surveys. In particular, we consider the local-type primordial non- Gaussianity and…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Ichihiko Hashimoto , Atsushi Taruya , Takahiko Matsubara , Toshiya Namikawa , Shuichiro Yokoyama

We forecast constraints on primordial non-Gaussianity achievable from forthcoming surveys by exploiting the scale-dependent halo bias introduced on large scales by non-Gaussian initial conditions. We explore the performance of exploiting…

Astrophysics · Physics 2010-03-26 Carmelita Carbone , Licia Verde , Sabino Matarrese

In the standard picture of structure formation, initially random-phase fluctuations are amplified by non-linear gravitational instability to produce a final distribution of mass which is highly non-Gaussian and has highly coupled Fourier…

Astrophysics · Physics 2009-10-31 Peter Coles , Lung-Yih Chiang

Next-generation galaxy and 21cm intensity mapping surveys will rely on a combination of the power spectrum and bispectrum for high-precision measurements of primordial non-Gaussianity. In turn, these measurements will allow us to…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-08 Roy Maartens , Sheean Jolicoeur , Obinna Umeh , Eline M. De Weerd , Chris Clarkson

In quasi-single field inflation models, massive isocurvature modes, that are coupled to the inflaton and have mass of order the Hubble parameter, can have nontrivial impacts on density perturbations, especially non-Gaussianities. We study a…

High Energy Physics - Theory · Physics 2010-05-07 Xingang Chen , Yi Wang