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Several claims have been made of anomalies in the large-angle properties of the cosmic microwave background anisotropy as measured by WMAP. In most cases, the statistical significance of these anomalies is hard or even impossible to assess,…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-11 Emory F. Bunn

We propose a novel representation of cosmic microwave anisotropy maps, where each multipole order l is represented by l unit vectors pointing in directions on the sky and an overall magnitude. These "multipole vectors and scalars" transform…

Astrophysics · Physics 2008-11-26 C. J. Copi , D. Huterer , G. D. Starkman

We have independently measured the genus topology of the temperature fluctuations in the cosmic microwave background seen in the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data. A genus analysis of the WMAP data indicates…

The quadrupole power of cosmic microwave background (CMB) temperature anisotropies seen in the WMAP data is puzzlingly low. In this paper we demonstrate that Minimum Variance Optimization (MVO), a technique used by many authors (including…

Astrophysics · Physics 2009-03-18 Lung-Yih Chiang , Pavel D. Naselsky , Peter Coles

We examine the constraints cosmological observations can place on any trans-Planckian corrections to the primordial spectrum of perturbations underlying the anisotropies in the Cosmic Microwave Background. We focus on models of…

Astrophysics · Physics 2011-05-12 Richard Easther , William H Kinney , Hiranya Peiris

We have independently measured the genus topology of the temperature fluctuations in the cosmic microwave background seen by the Wilkinson Microwave Anisotropy Probe (WMAP). A genus analysis of the WMAP data indicates consistency with…

Astrophysics · Physics 2011-05-10 Wesley N. Colley , J. Richard Gott

Statistical isotropy (SI) has been one of the simplifying assumptions in cosmological model building. Experiments like WMAP and PLANCK are attempting to test this assumption by searching for specific signals in the Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-21 Aditya Rotti , Moumita Aich , Tarun Souradeep

We review the recently found large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. These include alignments of the largest modes of CMB anisotropy with each other and with geometry and direction…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-10 Craig J. Copi , Dragan Huterer , Dominik J. Schwarz , Glenn D. Starkman

We argue that the observed large-scale cosmic microwave anomalies, discovered by WMAP and confirmed by the Planck satellite, are most naturally explained in the context of a marginally-open universe. Particular focus is placed on the dipole…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 Andrew R Liddle , Marina Cortês

Cosmic microwave background (CMB) experiments generally infer a temperature fluctuation from a measured intensity fluctuation through the first term in the Taylor expansion of the Planck function, the relation between the intensity in a…

Astrophysics · Physics 2009-11-07 M. Kamionkowski , Lloyd Knox

We study the apparent lack of power on large angular scales in the WMAP data. We confirm that although there is no apparent lack of power at large angular scales for the full-sky maps, the lowest multipoles of the WMAP data happen to have…

Astrophysics · Physics 2007-05-23 Amir Hajian

We study a specific correlation in spherical harmonic multipole domain for cosmic microwave background (CMB) analysis. This group of correlation between \Delta l=4n, n=1,2... is caused by symmetric signal in the Galactic coordinate system.…

Astrophysics · Physics 2009-11-13 Pavel D. Naselsky , Igor D. Novikov , Lung-Yih Chiang

Non-trivial spatial topology of the Universe may give rise to potentially measurable signatures in the cosmic microwave background. We explore different machine learning approaches to classify harmonic-space realizations of the microwave…

The ellipticity of the anisotropy spots of the Cosmic Microwave Background measured by the Wilkinson Microwave Anisotropy Probe (WMAP) has been studied. We find an average ellipticity of about 2, confirming with a far larger statistics…

Significant alignment and signed-intensity anomalies of local features of the cosmic microwave background (CMB) are detected on the three-year WMAP data, through a decomposition of the signal with steerable wavelets on the sphere. Firstly,…

Astrophysics · Physics 2009-09-29 P. Vielva , Y. Wiaux , E. Martinez-Gonzalez , P. Vandergheynst

An introduction to topological defects in cosmology is given. We discuss their possible relevance for structure formation. Especial emphasis is given on the signature of topological defects in the spectrum of anisotropies in the cosmic…

Astrophysics · Physics 2007-05-23 Ruth Durrer

We cross-correlate the cosmic microwave background temperature anisotropy maps from the WMAP, MAXIMA-I, and MAXIMA-II experiments. We use the cross-spectrum, which is the spherical harmonic transform of the angular two-point correlation…

The origin of small deviations from statistical isotropy in the Cosmic Microwave Background (CMB) - the so-called CMB anomalies - remains an open question in modern cosmology. In this work, we test statistical isotropy in Planck Data…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-09 C. Gimeno-Amo , F. K. Hansen , E. Martínez-González , R. B. Barreiro , A. J. Banday

We study the complex visibilities of the cosmic microwave background anisotropies that are observables in interferometric observations of the cosmic microwave background, using the multipole expansion methods commonly adopted in analyzing…

Astrophysics · Physics 2009-12-31 Kin-Wang Ng

The Wilkinson Microwave Anisotropy Probe (WMAP) mapped the distribution of temperature and polarization over the entire sky in five microwave frequency bands. These full-sky maps were used to obtain measurements of temperature and…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Eiichiro Komatsu , Charles L. Bennett