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A description of CMB temperature fluctuations beyond the power spectrum is important for verifying models of structure formation, especially in view of forthcoming high-resolution observations. We argue that higher-order statistics of…

Astrophysics · Physics 2007-05-23 S. Winitzki , J. H. P. Wu

Gravitational lensing of the Cosmic Microwave Background (CMB) encodes cosmological information in the observed anisotropies of temperature and polarization. Accurate extraction of this additional information requires precise modeling of…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-07 Aurélien Benoit-Lévy , Kendrick M. Smith , Wayne Hu

We explore the use of galaxy bispectra with multitracer technique as a possible probe of primordial non-Gaussianities. We forecast future constraints on non-linearity parameters, $f_{\rm NL}^{\rm eq}$ and $f_{\rm NL}^{\rm orth}$, which…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-12 Daisuke Yamauchi , Shuichiro Yokoyama , Keitaro Takahashi

Modes with wavelengths larger than the survey window can have significant impact on the covariance within the survey window. The supersample covariance has been recognized as an important source of covariance for the power spectrum on small…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 Kwan Chuen Chan , Azadeh Moradinezhad Dizgah , Jorge Noreña

Cosmic Microwave Background (CMB) Anisotropies is a subject of intensive research in several fields of sciences. In this paper we start a systematic development of basic notions and theory in statistics according to the application for CMB.…

Applications · Statistics 2013-12-30 Gyorgy Terdik

We investigate, in dark matter and galaxy mocks, the effects of approximating the galaxy power spectrum-bispectrum estimated covariance as a diagonal matrix, for an analysis that aligns with the specifications of recent and upcoming galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-12 Sergi Novell-Masot , Héctor Gil-Marín , Licia Verde

The population of compact extragalactic sources contribute to the non-Gaussianity at Cosmic Microwave Background frequencies. We study their non-Gaussianity using publicly available full-sky simulations. We introduce a parametrisation to…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-22 Fabien Lacasa

The normalisation of the matter power spectrum, sigma_8, is an essential ingredient to predict the phenomenology of the low redshift universe. It has been measured using several methods, such as X-ray cluster counts, weak lensing and the…

Astrophysics · Physics 2008-11-26 A. Amara , A. Refregier

Gravitational clustering is an intrinsically non-linear process that generates significant non-Gaussian signatures in the density field. We consider how these affect power spectrum determinations from galaxy and weak-lensing surveys.…

Astrophysics · Physics 2008-11-26 Roman Scoccimarro , Matias Zaldarriaga , Lam Hui

We derive in this paper expressions for the covariance matrix of the cosmic shear two-point correlation functions which are readily applied to any survey geometry. Furthermore, we consider the more special case of a simple survey geometry…

Astrophysics · Physics 2009-11-07 Peter Schneider , Ludovic van Waerbeke , Martin Kilbinger , Yannick Mellier

In cosmic shear likelihood analyses the covariance is most commonly assumed to be constant in parameter space. Therefore, when calculating the covariance matrix (analytically or from simulations), its underlying cosmology should not…

Astrophysics · Physics 2015-05-13 Tim Eifler , Peter Schneider , Jan Hartlap

This paper considers a multivariate spatial random field, with each component having univariate marginal distributions of the skew-Gaussian type. We assume that the field is defined spatially on the unit sphere embedded in $\mathbb{R}^3$,…

Statistics Theory · Mathematics 2017-10-05 Alfredo Alegría , Sandra Caro , Moreno Bevilacqua , Emilio Porcu , Jorge Clarke

The covariance matrix of the matter power spectrum is a key element of the statistical analysis of galaxy clustering data. Independent realisations of observational measurements can be used to sample the covariance, nevertheless statistical…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-14 Linda Blot , Pier Stefano Corasaniti , Luca Amendola , Thomas D. Kitching

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

We use the measurement of the cosmic microwave background taken during the MAXIMA-1 flight to estimate the bispectrum of cosmological perturbations. We propose an estimator for the bispectrum that is appropriate in the flat sky…

The non-Gaussian part of the covariance matrix of the galaxy power spectrum involves the connected four-point correlation in Fourier space, i.e. trispectrum. This paper introduces a fast method to compute the non-Gaussian part of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-07 Yosuke Kobayashi

In the context of the present and future Cosmic Microwave Background (CMB) experiments, going beyond the information provided by the power spectrum has become necessary in order to tightly constrain the cosmological model. The non-Gaussian…

Astrophysics · Physics 2008-11-26 N. Aghanim , M. Kunz , P. G. Castro , O. Forni

We present a general method for Bayesian inference of the underlying covariance structure of random fields on a sphere. We employ the Bipolar Spherical Harmonic (BipoSH) representation of general covariance structure on the sphere. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Santanu Das , Benjamin D. Wandelt , Tarun Souradeep

To combine information from measurements of the redshift-space power spectrum from spectroscopic data with angular weak lensing, galaxy clustering and galaxy-galaxy lensing power spectra from photometric surveys (i.e. the $3 \times 2$ point…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Peter L. Taylor , Katarina Markovič

(Abridged) Estimating the uncertainty on the matter power spectrum internally (i.e. directly from the data) is made challenging by the simple fact that galaxy surveys offer at most a few independent samples. In addition, surveys have…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Joachim Harnois-Deraps , Ue-Li Pen
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