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Related papers: Limits on Second-Order Non-Gaussianity from Minkow…

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We performed a comprehensive statistical analysis using complex phases of the a_lm coefficients computed from the most recent data of the Wilkinson Microwave Anisotropy Probe (WMAP). Our aim was to confirm or constrain the presence of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 András Kovács , István Szapudi , Zsolt Frei

An optimal method to constrain the non-linearity parameter g_NL of the local-type non-Gaussianity from CMB data is proposed. Our optimal estimator for g_NL is separable and can be efficiently computed in real space. Combining the exact…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-03 Toyokazu Sekiguchi , Naoshi Sugiyama

We investigate optimization strategies to measure primordial non-Gaussianity with future spectroscopic surveys. We forecast measurements coming from the 3D galaxy power spectrum and compute constraints on primordial non-Gaussianity…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Alvise Raccanelli , Olivier Dore , Neal Dalal

A detection of the level of non-Gaussianity in the CMB data is essential to discriminate among inflationary models and also to test alternative primordial scenarios. However, the extraction of primordial non-Gaussianity is a difficult…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-07 A. Bernui , M. J. Reboucas , A. F. F. Teixeira

Is there new physics hidden in the four-point function of the cosmic microwave background (CMB)? We conduct a detailed analysis of the Planck PR4 temperature and polarization trispectrum for $\ell\in[2,2048]$. Using the theoretical and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-30 Oliver H. E. Philcox

Non-linear CMB temperature anisotropies up to the third-order on large scales are calculated. On large scales and in the Sachs-Wolfe limit, we give the explicit expression for the observed temperature anisotropy in terms of the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-13 Xian Gao

The primordial non-Gaussianity (PNG) in matter density perturbation is a very powerful probe of the physics of the very early Universe. The local PNG can induce a distinct scale-dependent bias on the large scale structure distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-26 Yan Gong , Xin Wang , Zheng Zheng , Xuelei Chen

We evaluate the angular bispectrum of the CMB temperature anisotropy at large angular scale due to a stochastic background of primordial magnetic fields. The shape of non-Gaussianity depends on the spectral index of the magnetic field power…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-02 Chiara Caprini , Fabio Finelli , Daniela Paoletti , Antonio Riotto

We forecast combined future constraints from the cosmic microwave background and large-scale structure on the models of primordial non-Gaussianity. We study the generalized local model of non-Gaussianity, where the parameter f_NL is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Adam Becker , Dragan Huterer , Kenji Kadota

The cosmic microwave background radiation is supposed to be Gaussian and this hypothesis is in good agreement with the recent very accurate measurements. Nonetheless a tiny amount of non-Gaussianity is predicted by the standard inflation…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-06 Davide Pietrobon

Several conserved and/or gauge invariant quantities described as the second-order curvature perturbation have been given in the literature. We revisit various scenarios for the generation of second-order non-gaussianity in the primordial…

Astrophysics · Physics 2007-05-23 David H. Lyth , Yeinzon Rodriguez

Measurements of primordial non-Gaussianity ($f_{NL}$) open a new window onto the physics of inflation. We describe a fast cubic (bispectrum) estimator of $f_{NL}$, using a combined analysis of temperature and polarization observations. The…

Astrophysics · Physics 2009-02-23 Amit P. S. Yadav , Eiichiro Komatsu , Benjamin D. Wandelt

In the conference presentation we have reviewed the theory of non-Gaussian geometrical measures for the 3D Cosmic Web of the matter distribution in the Universe and 2D sky data, such as Cosmic Microwave Background (CMB) maps that was…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-19 Dmitri Pogosyan , Sandrine Codis , Christophe Pichon

To efficiently probe primordial non-Gaussianity using Cosmic Microwave Background (CMB) data, we require theoretical predictions that are factorizable, \textit{i.e.}\ those whose kinematic dependence can be separated. This property does not…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Oliver H. E. Philcox , Kunhao Zhong , Salvatore Samuele Sirletti

We consider a member of the family of scalar-tensor theories of Inflation - the so-called Horndeski model for Inflation, for which we calculate the non-Gaussianity (NG) and the power spectrum of curvature perturbations. We concentrate on…

General Relativity and Quantum Cosmology · Physics 2021-07-29 Avneet Singh

We study the $TT\mu$ bispectrum, generated by correlations between Cosmic Microwave Background temperature (T) anisotropies and chemical potential ($\mu$) distortions, and we analyze its dependence on primordial local trispectrum parameters…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-17 Nicola Bartolo , Michele Liguori , Maresuke Shiraishi

We study the covariance in the angular power spectrum estimates of CMB fluctuations when the primordial fluctuations are non-Gaussian. The non-Gaussian covariance comes from a nonzero connected four-point correlation function -- or the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-07 Saroj Adhikari , Dragan Huterer

The first year Wilkinson Microwave Anisotropy Probe (WMAP) set quantitative constraints on the amplitude of any primordial non-Gaussianity. We run a series of dark matter-only N-body simulations with the WMAP constraints to investigate the…

Astrophysics · Physics 2008-11-26 X. Kang , P. Norberg , J. Silk

Primordial non-Gaussianity can source $\mu$-distortion anisotropies that are correlated with the large-scale temperature and polarization signals of the cosmic microwave background (CMB). A measurement of $\mu T$ and $\mu E$ correlations…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Aditya Rotti , Andrea Ravenni , Jens Chluba

We constrain cosmological models where the primordial perturbations have both an adiabatic and a (possibly correlated) cold dark matter (CDM) or baryon isocurvature component. We use both a phenomenological approach, where the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-09 Jussi Valiviita , Matti Savelainen , Marianne Talvitie , Hannu Kurki-Suonio , Stanislav Rusak
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