English
Related papers

Related papers: Multipole vector anomalies in the first-year WMAP …

200 papers

We have investigated the angular correlation in the recent CMB data. In addition to the known large-angle correlation anomaly, we find the lack of correlation at small angles with high statistical significance. We have investigated various…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-14 Jaiseung Kim , Pavel Naselsky

We report the detection of a high Galactic latitude, large scale, 7-sigma signal in WMAP 5yr and spatially correlated with the ecliptic plane. Two possible candidates are studied, namely unresolved sources and Zodiacal light emission. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 J. M Diego , M. Cruz , J. Gonzalez-Nuevo , M. Maris , Y. Ascasibar , C. Burigana

The temperature anisotropy power spectrum measured with the Wilkinson Microwave Anisotropy Probe (WMAP) at high multipoles is in spectacular agreement with an inflationary Lambda-dominated cold dark matter cosmology. However, the low order…

Astrophysics · Physics 2009-11-07 G. Efstathiou

We perform an independent foreground analysis of the WMAP maps to produce a cleaned CMB map (available online) useful for cross-correlation with, e.g., galaxy and X-ray maps. We use a variant of the Tegmark & Efstathiou (1996) technique…

Astrophysics · Physics 2009-10-07 Max Tegmark , Angelica de Oliveira-Costa , Andrew Hamilton

We propose a framework for separating the information contained in the CMB multipoles, $a_{\ell m}$, into its algebraically independent components. Thus we cleanly separate information pertaining to the power spectrum, non-Gaussianity and…

Astrophysics · Physics 2009-11-10 Kate Land , Joao Magueijo

We test the hemispherical power asymmetry of the WMAP 7-year low-resolution temperature and polarization maps. We consider two natural estimators for such an asymmetry and exploit our implementation of an optimal angular power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 F. Paci , A. Gruppuso , F. Finelli , A. De Rosa , N. Mandolesi , P. Natoli

We report on the results from two independent but complementary statistical analyses of the WMAP first-year data, based on the power spectrum and N-point correlation functions. We focus on large and intermediate scales (larger than about 3…

Astrophysics · Physics 2009-11-10 H. K. Eriksen , F. K. Hansen , A. J. Banday , K. M. Gorski , P. B. Lilje

New analysis confirms our earlier claim [1], [7] of circles of notably low temperature variance, often in concentric sets, in the cosmic microwave background (CMB), discernable in WMAP data. Their reality can be interpreted as evidence of…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-04 V. G. Gurzadyan , R. Penrose

Obscuration due to Galactic emission complicates the extraction of information from cosmological surveys, and requires some combination of the (typically imperfect) modeling and subtraction of foregrounds, or the removal of part of the sky.…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-14 Stephen M. Feeney , Hiranya V. Peiris , Andrew Pontzen

WMAP observations have accurately determined the position of the first two peaks and dips in the CMB temperature power spectrum. These encode information on the ratio of the distance to the last scattering surface to the sound horizon at…

Astrophysics · Physics 2008-11-26 Pier Stefano Corasaniti , Alessandro Melchiorri

A previous work (Monteser\'in et al. 2008) estimated the CMB variance from the three-year WMAP data, finding a lower value than expected from Gaussian simulations using the WMAP best-fit cosmological model. We repeat the analysis on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Cruz , P. Vielva , E. Martínez-González , R. B. Barreiro

The low multipole anomalies of the Cosmic Microwave Background has received much attention during the last few years. It is still not ascertained whether these anomalies are indeed primordial or the result of systematics or foregrounds. An…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-01 M. Hansen , J. Kim , A. M. Frejsel , S. Ramazanov , P. Naselsky , W. Zhao , C. Burigana

We study the directional dependence of the angular two-point correlation function in maps of the cosmic microwave background (CMB). We propose two new statistics, one which measures the correlation of each point in the sky with a ring of…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-20 Sophie Zhang

The dipolar model \cite{Gordon:2005ai} has attracted much interest because it may phenomenologically explain the CMB hemispherical power asymmetry found in the WMAP and Planck data. Since such a model explicitly breaks isotropy at large…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-24 L. Polastri , A. Gruppuso , P. Natoli

I discuss whether the standard cosmological models fit the WMAP data well enough to justify parameter estimation with standard assumptions. The observed quadrupole is low (but has significant foreground uncertainty) and drives weak evidence…

Astrophysics · Physics 2017-08-23 Antony Lewis

We analyze the alignment of the low multipoles (quadrupole and octupole) of various maps of the WMAP 5yr release: the CMB maps obtained with ILC and MCMC methods, the CMB map in the V band after foreground reduction, and, for comparison,…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Alessandro Gruppuso , Carlo Burigana

Recently, full sky maps from Planck have been made publicly available. In this paper, we do consistency tests for the three Planck CMB sky maps. We assume that the difference between two maps represents the contributions from systematics,…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-27 Anne Mette Frejsel , Martin Hansen , Hao Liu

We consider the issue of hemispherical power asymmetry in the three-year WMAP data, adopting a previously introduced modulation framework. Computing both frequentist probabilities and Bayesian evidences, we find that the model consisiting…

Astrophysics · Physics 2009-11-13 H. K. Eriksen , A. J. Banday , K. M. Gorski , F. K. Hansen , P. B. Lilje

We reexamine the evidence of the hemispherical power asymmetry, detected in the CMB WMAP data using a new method. At first, we analyze the hemispherical variance ratios and compare these with simulated distributions. Secondly, working…

Astrophysics · Physics 2014-11-18 Bartosz Lew

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