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Destriping methods for constructing maps of the Cosmic Microwave Background (CMB) anisotropies have been investigated extensively in the literature. However, their error properties have been studied in less detail. Here we present an…

Astrophysics · Physics 2009-11-10 G. Efstathiou

We investigate the non-gaussian properties of cosmic-string-seeded linear density perturbations with cold and hot dark matter backgrounds, using high-resolution numerical simulations. We compute the one-point probability density function of…

Astrophysics · Physics 2009-10-30 P. P. Avelino , E. P. S. Shellard , J. H. P. Wu , B. Allen

The simplest inflationary models present us with few observable parameters to discriminate between them. A detection of features in the spectra of primordial density perturbations could provide valuable insights and lead to stringent tests…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-14 J. R. Fergusson , H. F. Gruetjen , E. P. S. Shellard , M. Liguori

We examine the effect of a threshold bias on the power spectrum and the bispectrum in an ensemble of numerical simulations (Gaussian initial perturbations with power law spectra P(k) \sim k^n, n=+1, 0, -1, -2) and compare our results with…

Astrophysics · Physics 2015-06-24 J. N. Fry , Adrian L. Melott , Sergei F. Shandarin

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 study the effects of instrumental systematics on the estimation of primordial non-Gaussianity using the cosmic microwave background (CMB) bispectrum from both the temperature and the polarization anisotropies. For temperature systematics…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-07 Meng Su , Amit P. S. Yadav , Meir Shimon , Brian G. Keating

In a first paper (Forni & Aghanim 1999), we developed several statistical discriminators to test the non-gaussian nature of a signal. These tests are based on the study of the coefficients in a wavelet decomposition basis. In this paper, we…

Astrophysics · Physics 2007-05-23 N. Aghanim , O. Forni

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

Cross-correlating the lensing signals of galaxies and comic microwave background (CMB) fluctuations is expected to provide valuable cosmological information. In particular it may help tighten constraints on parameters describing the…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-14 Philipp M. Merkel , Bjoern Malte Schaefer

We propose a new general method of extracting non-Gaussian features in a given field. It sets the mean of the field to zero and renormalizes its Fourier (or multipole) power to white noise, while keeping the phase information unchanged.…

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

We address the dual challenge of estimating deviations from Gaussianity arising in models of the Early Universe, whilst retaining information necessary to assess whether a detection of non-Gaussianity is primordial. We do this by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Dipak Munshi , Alan Heavens

We search the BOOMERanG maps of the anisotropy of the Cosmic Microwave Background (CMB) for deviations from gaussianity. In this paper we focus on analysis techniques in pixel-space, and compute skewness, kurtosis and Minkowski functionals…

The largest fluctuation in the observed CMB temperature field is the dipole, its origin being usually attributed to the Doppler Effect - the Earth's velocity with respect to the CMB rest frame. The lowest order boost correction to…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-28 Thiago S. Pereira , Amanda Yoho , Maik Stuke , Glenn D. Starkman

We discuss the effects of finite sky coverage and the uncertainty in extracting information about the power spectrum from experiments on small angular scales. In general the cosmic variance is enhanced by a factor of $4\pi/A$, where $A$ is…

Astrophysics · Physics 2009-10-22 Douglas Scott , Mark Srednicki , Martin White

Non-trivial spatial topology of the Universe can imprint potentially observable signatures on the cosmic microwave background (CMB). In this study, we investigate how deviations from the standard nearly-scale-free primordial power spectrum…

The extensive search for deviations from Gaussianity in cosmic microwave background radiation (CMB) data is very important due to the information about the very early moments of the universe encoded there. Recent analyses from Planck CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 C. P. Novaes , A. Bernui , I. S. Ferreira , C. A. Wuensche

An improved estimator for the amplitude fnl of local-type non-Gaussianity from the cosmic microwave background (CMB) bispectrum is discussed. The standard estimator is constructed to be optimal in the zero-signal (i.e., Gaussian) limit.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Tristan L. Smith , Daniel Grin , Marc Kamionkowski

The marked power spectrum - a two-point correlation function of a transformed density field - has emerged as a promising tool for extracting cosmological information from the large-scale structure of the Universe. In this work, we present…

We compute the effects induced by the use of small CMB maps on the measurement of the $\cl{l}$ coefficients of the angular power spectrum and show that small systematic effects have to be taken into account. We also compute numerically the…

Astrophysics · Physics 2007-08-06 C. Magneville , J. P. Pansart

Experiments involving the two-dimensional passive diffusion of colloidal boomerangs tracked off their centre of mobility have shown striking non-Gaussian tails in their probability distribution function [Chakrabarty et al., Soft Matter 12,…

Soft Condensed Matter · Physics 2018-04-18 Lyndon Koens , Maciej Lisicki , Eric Lauga