中文
相关论文

相关论文: Dominant Multipoles in WMAP5 Mosaic Data Correlati…

200 篇论文

We analyze first-year data of WMAP to determine the significance of asymmetry in summed power between arbitrarily defined opposite hemispheres, using maps that we create ourselves with software developed independently of the WMAP team. We…

天体物理学 · 物理学 2010-11-11 P. E. Freeman , C. R. Genovese , C. J. Miller , R. C. Nichol , L. Wasserman

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…

宇宙学与河外天体物理 · 物理学 2015-06-12 F. Paci , A. Gruppuso , F. Finelli , A. De Rosa , N. Mandolesi , P. Natoli

Recently a symmetry-based method to test for statistical isotropy of the cosmic microwave background was developed. We apply the method to template-cleaned 3-year and 5-year WMAP-$DA$ maps. We examine a wide range of angular multipoles from…

天体物理学 · 物理学 2010-11-02 Pramoda Kumar Samal , Rajib Saha , Pankaj Jain , John P. Ralston

Large-scale anomalies have been reported in CMB data with both WMAP and Planck data. These could be due to foreground residuals and or systematic effects, though their confirmation with Planck data suggests they are not due to a problem in…

宇宙学与河外天体物理 · 物理学 2015-06-19 A. Rassat , J. -L. Starck , P. Paykari , F. Sureau , J. Bobin

Following this astro-ph communication, we release a set of 10,000 WMAP ILC simulations, produced as described by Eriksen et al. (2004). We strongly encourage that an analysis of these simulations accompanies any scientific analysis of the…

天体物理学 · 物理学 2007-05-23 H. K. Eriksen , A. J. Banday , K. M. Gorski , P. B. Lilje

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…

天体物理学 · 物理学 2008-11-26 C. J. Copi , D. Huterer , G. D. Starkman

We have studied the cosmic microwave background (CMB) map looking for features beyond cosmological isotropy. We began by tiling the CMB variance map (which are produced by different smoothing scales) with stripes of different sizes along…

宇宙学与河外天体物理 · 物理学 2024-08-12 MohammadHossein Jamshidi , Abdolali Banihashemi , Nima Khosravi

The anomaly against the Gaussianity in the WMAP data was alleged to be due to insufficient handling of beam asymmetries. In this paper we investigate this issue and develop a method to estimate the shape of the inflight effective beam,…

宇宙学与河外天体物理 · 物理学 2015-06-17 Lung-Yih Chiang

We discuss the problem of the bias of the Internal Linear Combination (ILC) CMB map and show that it is closely related to the coefficient of cross-correlation K(l) of the true CMB and the foreground for each multipole l. We present…

天体物理学 · 物理学 2009-06-23 Pavel D. Naselsky , Oleg V. Verkhodanov , Mikkel T. B. Nielsen

The power spectrum is obtained for the Kolmogorov stochasticity parameter map for WMAP's cosmic microwave background (CMB) radiation temperature datasets. The interest for CMB Kolmogorov map is that it can carry direct information about…

宇宙学与河外天体物理 · 物理学 2015-05-14 V. G. Gurzadyan , A. L. Kashin , H. G. Khachatryan , A. A. Kocharyan , E. Poghosian , D. Vetrugno , G. Yegorian

Anomalous radio flux ratios in four-image gravitational lens systems can be explained by adding a clumpy cold dark matter (CDM) component to the potential of the lens galaxy. Evans & Witt (2003) recently suggested that smooth multipole…

天体物理学 · 物理学 2009-11-13 Arthur B. Congdon , Charles R. Keeton

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…

宇宙学与河外天体物理 · 物理学 2015-06-24 L. Polastri , A. Gruppuso , P. Natoli

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.…

天体物理学 · 物理学 2009-11-13 Pavel D. Naselsky , Igor D. Novikov , Lung-Yih Chiang

We study the large-scale angular correlation signatures of the Cosmic Microwave Background (CMB) temperature fluctuations from WMAP data in several spherical cap regions of the celestial sphere, outside the Kp0 or Kp2 cut-sky masks. We…

天体物理学 · 物理学 2008-11-26 Armando Bernui , Thyrso Villela , Carlos A. Wuensche , Rodrigo Leonardi , Ivan Ferreira

We apply our symmetry based Power tensor technique to test conformity of PLANCK Polarization maps with statistical isotropy. On a wide range of angular scales (l=40-150), our preliminary analysis detects many statistically anisotropic…

宇宙学与河外天体物理 · 物理学 2020-02-27 Pranati K. Rath , Pramoda Kr. Samal , Srikanta Panda , Debesh D. Mishra , Pavan K. Aluri

We study the Internal Linear Combination (ILC) method presented by the Wilkinson Microwave Anisotropy Probe (WMAP) science team, with the goal of determining whether it may be used for cosmological purposes, as a template-free alternative…

天体物理学 · 物理学 2009-07-09 H. K. Eriksen , A. J. Banday , K. M. Gorski , P. B. Lilje

The existing analysis of WMAP data is based on approximations for the likelihood function, which is likely to be inaccurate on large scales. Here we present exact evaluations of the likelihood of the low multipoles by direct inversion of…

天体物理学 · 物理学 2009-11-10 A. Slosar , U. Seljak , A. Makarov

We investigate anomalies reported in the Cosmic Microwave Background maps from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite on very large angular scales and discuss possible interpretations. Three independent anomalies involve…

天体物理学 · 物理学 2009-07-09 Angelica de Oliveira-Costa , Max Tegmark , Matias Zaldarriaga , Andrew Hamilton

Full-sky maps of the cosmic microwave background temperature reveal a 7% asymmetry of fluctuation power between two halves of the sky. A common phenomenological model for this asymmetry is an overall dipole modulation of statistically…

宇宙学与河外天体物理 · 物理学 2015-10-07 Simone Aiola , Bingjie Wang , Arthur Kosowsky , Tina Kahniashvili , Hassan Firouzjahi

One feature of the chiral anomaly, analyzed in a perturbative framework, is the appearance of massless poles which account for it. They are identified by a spectral analysis of the anomaly graph and are usually interpreted as being of an…

高能物理 - 唯象学 · 物理学 2009-12-15 Roberta Armillis , Claudio Coriano , Luigi Delle Rose