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We describe and discuss the application of Gumbel statistics, which model extreme events, to WMAP 5-year measurements of the cosmic microwave background. We find that temperature extrema of the CMB are well modelled by the Gumbel formalism…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-01 Gatis Mikelsons , Joseph Silk , Joe Zuntz

The identification and extraction of non-Gaussian signals is one of the main cosmological challenges facing future experimental measurements of the cosmic microwave background temperature pattern. We present a generalized statistical…

Astrophysics · Physics 2009-11-07 Lung-Yih Chiang , Pavel Naselsky , Peter Coles

Cosmic inflation may have led to non-Gaussian initial conditions that cannot be fully parametrised by 3- and/or 4-point functions. In this work, we discuss various strategies to search for primordial non-Gaussianity beyond polyspectra with…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-03 Gonzalo A. Palma , Bruno Scheihing Hitschfeld , Spyros Sypsas

The nonlinear parameter measures the amplitude of primordial non-Gaussianity in the cosmic microwave background radiation (CMB), offering a crucial test of early universe models. While standard single field inflation predicts nearly…

Statistics Theory · Mathematics 2025-07-11 Claudio Durastanti

Non-Gaussianities of dynamical origin are disentangled from primordial ones using the formalism of large deviation statistics with spherical collapse dynamics. This is achieved by relying on accurate analytical predictions for the one-point…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Cora Uhlemann , Enrico Pajer , Christophe Pichon , Takahiro Nishimichi , Sandrine Codis , Francis Bernardeau

Cross-correlations between Cosmic Microwave Background (CMB) temperature and $y$-spectral distortions anisotropies have been previously proposed as a way to measure the local bispectrum parameter $f_{\rm NL}^{\rm loc.}$ in a range of scales…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Andrea Ravenni , Michele Liguori , Nicola Bartolo , Maresuke Shiraishi

In the context of inflationary scenarios, the observed large angle anisotropy of the Cosmic Microwave Background (CMB) temperature is believed to probe the primordial metric perturbations from inflation. Although the perturbations from…

Astrophysics · Physics 2019-08-17 Somnath Bharadwaj , Dipak Munshi , Tarun Souradeep

We review in a pedagogical way the present status of the impact of non-Gaussianity (NG) on the Cosmic Microwave Background (CMB) anisotropies. We first show how to set the initial conditions at second-order for the (gauge invariant) CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 N. Bartolo , S. Matarrese , A. Riotto

In this paper we analyze the biasing effect of point sources, either thermal Sunyaev-Zeldovich clusters or standard radio sources, on the estimated strength of the non-Gaussianity in the Cosmic Microwave Background (CMB). We show that the…

Astrophysics · Physics 2008-11-26 Daniel Babich , Elena Pierpaoli

We propose several pseudoentropy measures that agree well with the Wehrl entropy, but are significantly faster to compute. All of them are rotationally invariant measures of entanglement very sensitive to non-Gaussianity, anisotropy, and…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-06 Momchil Minkov , Marvin Pinkwart , Peter Schupp

We analyze primordial non-Gaussianity in single field inflationary models when the tensor/scalar ratio is large. Our results show that detectable levels of non-Gaussianity $f_{NL} \sim 50$ are still possible in the simplest class of models…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-19 Guido D'Amico , Matthew Kleban

Why is non-Gaussianity interesting? One of generic predictions from inflationary scenarios is that primordial fluctuations are exactly Gaussian in linear order; however, the non-linearity in the inflation will produce weak non-Gaussianity.…

Astrophysics · Physics 2017-08-23 Eiichiro Komatsu , David N. Spergel

A convincing detection of primordial non-Gaussianity in the local form of the bispectrum, whose amplitude is given by the fNL parameter, offers a powerful test of inflation. In this paper we calculate the modification of two-point…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Donghui Jeong , Eiichiro Komatsu , Bhuvnesh Jain

Despite the wealth of $Planck$ results, there are difficulties in disentangling the primordial non-Gaussianity of the Cosmic Microwave Background (CMB) from the secondary and the foreground non-Gaussianity (NG). For each of these forms of…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-10 Thomas Buchert , Martin J. France , Frank Steiner

We present an upgraded combined estimator, based on Minkowski Functionals and Neural Networks, with excellent performance in detecting primordial non-Gaussianity in simulated maps that also contain a weighted mixture of Galactic…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 C. P. Novaes , A. Bernui , I. S. Ferreira , C. A. Wuensche

Many inflation models predict that primordial density perturbations have a nonzero three-point correlation function, or bispectrum in Fourier space. Of the several possibilities for this bispectrum, the most commmon is the local-model…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Razieh Emami , Emanuela Dimastrogiovanni , Jens Chluba , Marc Kamionkowski

We discuss how primordial (e.g. inflationary) non-Gaussianity in the cosmological perturbations is left imprinted in the Large-Scale Structure of the universe. Our findings show that the information on the primordial non-Gaussianity set on…

Astrophysics · Physics 2009-11-10 N. Bartolo , S. Matarrese , A. Riotto

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

Assuming a slow-roll inflationary model where conformal invariance of the Maxwell action is broken via a non-minimal kinetic coupling term, we investigate the non-Gaussian three-point cross-correlation function between the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-08 Arko Bhaumik , Supratik Pal

All the analyses of Cosmic Microwave Background (CMB) temperature maps up--to--date show that CMB anisotropies follow a Gaussian distribution. On the other hand, astrophysical foregrounds which hamper the detection of the CMB angular power…

Astrophysics · Physics 2008-11-26 F. Argüeso , J. González-Nuevo , L. Toffolatti