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We simulate Planck observations by adopting a detailed model of the microwave sky including monopole, dipole, anisotropies of the cosmic microwave background (CMB) and galactic and extragalactic foregrounds. We estimate the impact of main…

In this article, the possibility of generating non-classical light due to Planck-scale effects is considered. For this purpose, a widely studied model of deformation of the Heisenberg uncertainty relation is applied to single-mode and…

General Relativity and Quantum Cosmology · Physics 2024-11-07 Danilo Artigas , Killian Martineau , Jakub Mielczarek

We introduce an alternative parametrisation for the scale dependence of the non-linearity parameter $f_{\rm NL}$ in quasi-local models of non-Gaussianity. Our parametrisation remains valid when $f_{\rm NL}$ changes sign, unlike the commonly…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-02 Christian T. Byrnes , Ewan R. M. Tarrant

We analyze multi-field inflationary systems which yield strongly scale dependent non-Gaussianity with a shape that is very close to the local shape. As in usual multi-field models, the non-Gaussianity arises from the non-linear transfer of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-27 Jason Kumar , Louis Leblond , Arvind Rajaraman

Gaussian random fields pervade all areas of science. However, it is often the departures from Gaussianity that carry the crucial signature of the nonlinear mechanisms at the heart of diverse phenomena, ranging from structure formation in…

Statistical Mechanics · Physics 2015-06-05 T. H. Beuman , A. M. Turner , V. Vitelli

We consider corrections to the underlying cosmology due to secondary contributions from weak gravitational lensing, the integrated Sachs-Wolfe effect, and the Sunyaev-Zel'dovich effect contained in the trispectrum. We incorporate these…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-17 Joseph Smidt , Shahab Joudaki , Paolo Serra , Alexandre Amblard , Asantha Cooray

We investigate the power of geometrical estimators on detecting non-Gaussianity in the cosmic microwave background. In particular the number, eccentricity and Gaussian curvature of excursion sets above (and below) a threshold are studied.…

Astrophysics · Physics 2011-05-10 R. B. Barreiro , E. Martinez-Gonzalez , J. L. Sanz

Non-linear interactions during inflation generate non-Gaussianities in the distribution of primordial curvature. In many theories, the physics is scale-invariant, such that the induced three-point function depends solely on a dimensionless…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-27 Oliver H. E. Philcox

In curvaton-type models, observable non-gaussianity of the curvature perturbation would come from a contribution of the form $(\delta\sigma)^2$, where $\delta\sigma$ is gaussian. I analyse this situation allowing $\delta\sigma$ to be…

Astrophysics · Physics 2009-11-11 D. H. Lyth

In this letter we present constraints on the scale-dependent "local" type primordial non-Gaussianity, which is described by non-Gaussianity's spectral index $n_{\rm NG}$, from the NRAO VLA Sky Survey and the quasar catalog of the Sloan…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Ji-Ping Dai , Jun-Qing Xia

Using $N$-body simulations of cosmological large-scale structure formation, for the first time, we show that the anisotropic primordial non-Gaussianity (PNG) causes a scale-dependent modification, given by $1/k^2$ at small $k$ limit, in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 Kazuyuki Akitsu , Toshiki Kurita , Takahiro Nishimichi , Masahiro Takada , Satoshi Tanaka

Primordial scalar perturbations may be generated when complex conformal scalar field rolls down its negative quartic potential. We begin with the discussion of peculiar infrared properties of this scenario. We then consider the statistical…

High Energy Physics - Theory · Physics 2011-12-13 M. Libanov , S. Mironov , V. Rubakov

We study the Likelihood function of data given f_NL for the so-called local type of non-Gaussianity. In this case the curvature perturbation is a non-linear function, local in real space, of a Gaussian random field. We compute the…

Astrophysics · Physics 2010-10-27 Paolo Creminelli , Leonardo Senatore , Matias Zaldarriaga

Fluctuations with wavelengths larger than the volume of a galaxy survey affect the measurement of the galaxy power spectrum within the survey itself. In the presence of local Primordial Non- Gaussianities (PNG), in addition to the…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Emanuele Castorina , Azadeh Moradinezhad Dizgah

Several early Universe scenarios predict a direction-dependent spectrum of primordial curvature perturbations. This translates into the violation of the statistical isotropy of cosmic microwave background radiation. Previous searches for…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 S. Ramazanov , G. Rubtsov , M. Thorsrud , F. R. Urban

We studied the effect of primordial non-Gaussianity with varied bispectrum shapes on the number counts of signal-to-noise peaks in wide field cosmic shear maps. The two cosmological contributions to this particular weak lensing statistic,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 M. Maturi , C. Fedeli , L. Moscardini

We obtain a consistency relation for the observed three-point correlator of galaxies. It includes relativistic effects and it is valid in the squeezed limit. Furthermore, the consistency relation is non-perturbative and can be used at…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-19 A. Kehagias , A. Moradinezhad Dizgah , J. Noreña , H. Perrier , A. Riotto

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

The primordial non-Gaussianity parameters fNL and tauNL may be scale-dependent. We investigate the capability of future measurements of the CMB mu-distortion, which is very sensitive to small scales, and of the large-scale halo bias to test…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-27 Matteo Biagetti , Hideki Perrier , Antonio Riotto , Vincent Desjacques

We calculate the bispectrum, B_g(k_1,k_2,k_3), Fourier transform of the three-point function of density peaks (e.g., galaxies), using two different methods: the Matarrese-Lucchin-Bonometto formula and the locality of galaxy bias. The…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-28 Donghui Jeong , Eiichiro Komatsu