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Related papers: Simulation of non-Gaussian CMB maps

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Although theoretically expected to be Statistically Isotropic (SI), the observed Cosmic Microwave Background (CMB) temperature \& polarization field would exhibit SI violation due to various inevitable effects like weak lensing, Doppler…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-27 Suvodip Mukherjee , Tarun Souradeep

Recent second-order perturbation computations have provided an accurate prediction for the primordial gravitational potential $\Phi(x)$ in scenarios in which cosmological perturbations are generated either during or after inflation. This…

Astrophysics · Physics 2008-11-26 M. Liguori , F. K. Hansen , E. Komatsu , S. Matarrese , A. Riotto

We propose an alternative formalism to simulate CMB temperature maps in $\Lambda$CDM universes with nontrivial spatial topologies. This formalism avoids the need to explicitly compute the eigenmodes of the Laplacian operator in the spatial…

Astrophysics · Physics 2008-11-26 W. S. Hipolito-Ricaldi , G. I. Gomero

Primordial statistical anisotropy is a key indicator to investigate early Universe models and has been probed by the cosmic microwave background (CMB) anisotropies. In this paper, we examine tensor-mode CMB fluctuations generated from…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-29 Maresuke Shiraishi , David F. Mota , Angelo Ricciardone , Frederico Arroja

The statistical expectation values of the temperature fluctuations of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. We investigate the statistical isotropy of the CMB anisotropy maps recently…

Astrophysics · Physics 2007-05-23 Tarun Souradeep , Amir Hajian

One of the most powerful tools to probe the existence of cosmic defects in the early universe is through the Cosmic Microwave Background (CMB) radiation. It is well known that computations with causal sources are more involved than the…

Astrophysics · Physics 2007-05-23 Alejandro Gangui

We study the power of several scalar quantities constructed on the sphere (presented in Monteserin et al. 2005) to detect non-Gaussianity on the temperature distribution of the cosmic microwave background (CMB). The test has been performed…

Astrophysics · Physics 2009-11-11 C. Monteserin , R. B. Barreiro , E. Martinez-Gonzalez , J. L. Sanz

By actively distorting the Cosmic Microwave Background (CMB) over our past light cone, cosmic strings are unavoidable sources of non-Gaussianity. Developing optimal estimators able to disambiguate a string signal from the primordial type of…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-22 Christophe Ringeval , Francois R. Bouchet

The decomposition of a signal on the sphere with the steerable wavelet constructed from the second Gaussian derivative gives access to the orientation, signed-intensity, and elongation of the signal's local features. In the present work,…

Astrophysics · Physics 2009-11-13 Y. Wiaux , P. Vielva , R. B. Barreiro , E. Martinez-Gonzalez , P. Vandergheynst

We compare the latest results from CMB experiments at scales around $l_e \sim 150$ over different parts of the sky to test the hypothesis that they are drawn from a Gaussian distribution, as is usually assumed. Using both the diagonal and…

Astrophysics · Physics 2009-10-30 E. Gaztanaga , P. Fosalba , E. Elizalde

Upcoming surveys will measure the cosmic microwave background (CMB) weak lensing power spectrum in exquisite detail, allowing for strong constraints on the sum of neutrino masses among other cosmological parameters. Standard CMB lensing…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-23 Delon Shen , Emmanuel Schaan , Simone Ferraro

We present a complete set of formulae for calculating the bispectra of CMB temperature and polarization anisotropies generated from non-Gaussianity in the vector and tensor mode perturbations. In the all-sky analysis it is found that the…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-11 Maresuke Shiraishi , Shuichiro Yokoyama , Daisuke Nitta , Kiyotomo Ichiki , Keitaro Takahashi

Non-gaussianity represents the statistical signature of physical processes such as turbulence. It can also be used as a powerful tool to discriminate between competing cosmological scenarios. A canonical analysis of non-gaussianity is based…

Astrophysics · Physics 2009-10-31 O. Forni , N. Aghanim

We investigate the properties of the (complex) coefficients obtained in a spherical harmonic representation of temperature maps of the cosmic microwave background (CMB). We study the effect of the coefficient phase only, as well as the…

Astrophysics · Physics 2009-11-10 Andrew Stannard , Peter Coles

In the context of the geometrical analysis of weakly non Gaussian CMB maps, the 2D differential extrema counts as functions of the excursion set threshold is derived from the full moments expansion of the joint probability distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Dmitri Pogosyan , Christophe Pichon , Christophe Gay

Searching for and charactering the non-Gaussianity (NG) of a given field has been a vital task in many fields of science, because we expect the consequences of different physical processes to carry different statistical properties. Here we…

Astrophysics · Physics 2007-05-23 Jiun-Huei Proty Wu

As well as primary fluctuations, CMB temperature maps contain a wealth of additional information in the form of secondary anisotropies. Secondary effects that can be identified with individual objects, such as the thermal and kinetic…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-19 Philip Bull , Ingunn K. Wehus , Hans Kristian Eriksen , Pedro G. Ferreira , Unni Fuskeland , Krzysztof M. Gorski , Jeffrey B. Jewell

The angular power spectrum of the Cosmic Microwave Background (CMB) anisotropies is a key tool to study the Universe. However, it is blind to the presence of non--Gaussianities and deviations from statistical isotropy, which instead can be…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-26 Alessandro Carones , Javier Carrón Duque , Domenico Marinucci , Marina Migliaccio , Nicola Vittorio

The statistical properties of the temperature anisotropies and polarization of the of cosmic microwave background (CMB) radiation offer a powerful probe of the physics of the early universe. In recent works a statistical procedure based…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 M. J. Reboucas , A. Bernui

We discuss the requirements of good statistics for quantifying non-Gaussianity in the Cosmic Microwave Background. The importance of rotational invariance and statistical independence is stressed, but we show that these are sometimes…

Astrophysics · Physics 2011-05-10 Pedro G. Ferreira , Joao Magueijo , Joseph Silk