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We study the angular distribution of temperature fluctuations in the cosmic microwave background (CMB) to probe the statistical isotropy of the universe by using precise full-sky CMB data with a model-independent approach. We investigated…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-01 C. E. Kester , A. Bernui , W. S. Hipólito-Ricaldi

We use simulated maps of the cosmic microwave background anisotropy to quantify the ability of different statistical tests to discriminate between Gaussian and non-Gaussian models. Despite the central limit theorem on large angular scales,…

Astrophysics · Physics 2009-10-31 Nicholas G. Phillips , A. Kogut

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

A total angular momentum representation simplifies the radiation transport problem for temperature and polarization anisotropy in the CMB. Scattering terms couple only the quadrupole moments of the distributions and each moment corresponds…

Astrophysics · Physics 2009-08-18 Wayne Hu , Martin White

South Pole Station offers a unique combination of high, dry, stable conditions and well-developed support facilities. Over the past 20 years, a sequence of increasingly sophisticated CMB experiments at Pole have built on the experience of…

Astrophysics · Physics 2007-07-10 J. M. Kovac , D. Barkats

Several accurate analyses of the CMB temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed a set of anomalous results, at large angular scales, that appears inconsistent with the statistical isotropy expected…

Astrophysics · Physics 2009-07-22 A. Bernui , W. S. Hipolito-Ricaldi

We present an analytic approach to the estimation of beam asymmetry effects in CMB temperature and linear polarization anisotropy experiments. We derive via perturbative expansions simple and accurate results for the case of an elliptical…

Astrophysics · Physics 2009-11-06 P. Fosalba , O. Doré , F. R. Bouchet

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

Secondary anisotropies in the cosmic microwave background (CMB) contain information that can be used to test both cosmological models and models of galaxy formation. Starting from lightcone-based HEALPix maps and catalogues, we present a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-22 Tianyi Yang , Ian G. McCarthy , Fiona McCarthy , Boris Bolliet , Jens Chluba , William Coulton , John C. Helly , Matthieu Schaller , Joop Schaye

We present a phenomenological investigation of non-Gaussian effects that could be seen on CMB temperature maps. Explicit expressions for the temperature correlation functions are given for different types of primordial mode couplings. We…

Astrophysics · Physics 2011-01-20 T. Brunier , F. Bernardeau

Recently, it was shown that local variance maps of temperature anisotropy are simple and useful tools for the study of large scale hemispherical power asymmetry. This was done by studying the distribution of dipoles of the local variance…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-12 Saroj Adhikari

Our peculiar velocity with respect to the CMB rest frame is known to induce a large dipole in the CMB. However, the motion of an observer has also the effect of distorting the anisotropies at all scales, as shown by Challinor and Van…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-07 Luca Amendola , Riccardo Catena , Isabella Masina , Alessio Notari , Miguel Quartin , Claudia Quercellini

Statistical Isotropy of the Cosmic Microwave Background (CMB) radiation has been studied and debated extensively in recent years. Under this assumption, the hot spots and cold spots of the CMB are expected to be uniformly distributed over a…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-14 Md Ishaque Khan , Rajib Saha

While the observed nearly scale-invariant initial power spectrum is regarded as one of the favorable evidence of the standard inflationary cosmology, precision observations of the Cosmic Microwave Background (CMB) anisotropies also suggest…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-06 Koichiro Horiguchi , Kiyotomo Ichiki , Jun'ichi Yokoyama

CMB spectral distortions are induced by Compton collisions with electrons. We review the various schemes to characterize the anisotropic CMB with a non-Planckian spectrum. We advocate using logarithmically averaged temperature moments as…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-06 Cyril Pitrou , Albert Stebbins

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

We present a detailed analytical calculation of CMB temperature anisotropies \alpha_k and polarization \beta_k generated by scalar metric perturbations in synchronous gauge, parallel to our previous work with RGW as a generating source.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Zheng Cai , Yang Zhang

ABRIDGED: We introduce and analyze a method for testing statistical isotropy and Gaussianity and apply it to the WMAP CMB foreground reduced, temperature maps, and cross-channel difference maps. We divide the sky into regions of varying…

Astrophysics · Physics 2009-06-23 Bartosz Lew

We calculate temperature anisotropies of the cosmic microwave background (CMB) for several initial power spectra of density perturbations with a built-in scale suggested by recent optical data on the spatial distribution of rich clusters of…

Astrophysics · Physics 2009-10-30 F. Atrio-Barandela , J. Einasto , S. Gottlöber , V. Müller , A. A. Starobinsky

In the present work, we study the largest structures of the CMB temperature measured by Planck in terms of the most prominent peaks on the sky, which, in particular, are located in the southern galactic hemisphere. Besides these large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 A. Marcos-Caballero , E. Martínez-González , P. Vielva