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相关论文: Parity Asymmetry in the CMBR Temperature Power Spe…

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The standard cosmological model is assumed to respect parity symmetry. Under this assumption the cross-correlations of the CMB's temperature anisotropy and `gradient'-like polarization, with the `curl'-like polarization identically vanish…

宇宙学与河外天体物理 · 物理学 2009-10-29 N. J. Miller , M. Shimon , B. G. Keating

Large-scale modes in the temperature anisotropy power spectrum C_l measured by the Wilkinson Microwave Anisotropy Probe (WMAP), seem to have lower amplitudes (C_2, C_3 and C_4) than that expected in the so called concordance LCDM model. In…

天体物理学 · 物理学 2009-11-07 E. Gaztanaga , J. Wagg , T. Multamaki , A. Montana , D. H. Hughes

We present an updated data-analysis comparison of the most recent observations of the Cosmic Microwave Background temperature anisotropies and polarization angular power spectra released by four different experiments: the Planck satellite…

宇宙学与河外天体物理 · 物理学 2022-11-15 Eleonora Di Valentino , William Giarè , Alessandro Melchiorri , Joseph Silk

Our peculiar motion with respect to the CMB rest frame represents a preferred direction in the observed CMB sky since it induces an apparent deflection of the observed CMB photons (aberration) and a shift in their frequency (Doppler). Both…

宇宙学与河外天体物理 · 物理学 2015-07-01 Alessio Notari , Miguel Quartin , Riccardo Catena

We propose a dipole modulation model for the Cosmic Microwave Background Radiation (CMBR) polarization field. We show that the model leads to correlations between l and l+1 multipoles, exactly as in the case of temperature. We obtain…

宇宙学与河外天体物理 · 物理学 2017-10-31 Shamik Ghosh , Rahul Kothari , Pankaj Jain , Pranati K. Rath

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

The lack of power anomaly is an intriguing feature at the largest angular scales of the CMB anisotropy temperature pattern, whose statistical significance is not strong enough to claim any new physics beyond the standard cosmological model.…

宇宙学与河外天体物理 · 物理学 2019-06-11 M. Billi , A. Gruppuso , N. Mandolesi , L. Moscardini , P. Natoli

We investigate a possible asymmetry in the statistical properties of the cosmic microwave background temperature field and to do so we construct an estimator aiming at detecting a dipolar modulation. Such a modulation is found to induce…

天体物理学 · 物理学 2009-11-10 Simon Prunet , Jean-Philippe Uzan , Francis Bernardeau , Tristan Brunier

The origin of power asymmetry and other measures of statistical anisotropy on the largest scales of the universe, as manifested in Cosmic Microwave Background (CMB) and large-scale structure data, is a long-standing open question in…

宇宙学与河外天体物理 · 物理学 2021-05-12 Pablo Fosalba , Enrique Gaztanaga

We show that the popular ILC approach is unstable in respect to the division of the sample of map pixels to the set of ``homogeneous'' subsamples. For suitable choice of such subsamples we can obtain the restored CMB signal with amplitudes…

宇宙学与河外天体物理 · 物理学 2011-02-18 A. Doroshkevich , O. Verkhodanov

We undertake a reassessment of one of the large angular scale anomalies observed in cosmic microwave background (CMB) temperature signal referred to as Hemispherical Power Asymmetry (HPA). For the present analysis we use \texttt{SEVEM}…

宇宙学与河外天体物理 · 物理学 2026-02-17 Sanjeev Sanyal , Sanjeet K. Patel , Pavan K. Aluri , Arman Shafieloo

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

Breakdown of rotational invariance of the primordial power spectrum manifests in the statistical anisotropy of the observed Cosmic Microwave Background (CMB) radiation. Hemispherical power asymmetry in the CMB may be caused due to a dipolar…

宇宙学与河外天体物理 · 物理学 2023-05-23 Md Ishaque Khan , Rajib Saha

The first year results of WMAP tentatively indicate running of the spectral index as well as a deficit of power in the low multipoles in the CMB spectrum. The former can be rather easily understood in the noncommutative inflation model, and…

天体物理学 · 物理学 2009-11-10 Qing-Guo Huang , Miao Li

We present new full-sky temperature maps in five frequency bands from 23 to 94 GHz, based on the first three years of the WMAP sky survey. The new maps, which are consistent with the first-year maps and more sensitive, incorporate…

The low quadrupole of the cosmic microwave background (CMB), measured by COBE and confirmed by WMAP, has generated much discussion recently. We point out that the well-known correlation between temperature and polarization anisotropies of…

天体物理学 · 物理学 2009-06-15 Olivier Doré , Gilbert P. Holder , Abraham Loeb

We estimate the power spectra of CMB temperature anisotropy in localized regions on the sky using the WMAP 7-year data. Here, we report that the north hat and the south hat regions at the high Galactic latitude (|b| >= 30 deg) show anomaly…

宇宙学与河外天体物理 · 物理学 2017-01-18 Kyeong Yeon Ko , Chan-Gyung Park , Jai-chan Hwang

We examine Cosmic Microwave Background (CMB) temperature power spectra from the BOOMERANG, MAXIMA, and DASI experiments. We non-parametrically estimate the true power spectrum with no model assumptions. This is a significant departure from…

天体物理学 · 物理学 2007-05-23 Christopher J. Miller , Robert C. Nichol , Christopher Genovese , Larry Wasserman

We present a joint cosmological analysis combining data from the Planck satellite, the Atacama Cosmology Telescope, and the South Pole Telescope. We construct a unified likelihood that reproduces the measured temperature and polarisation…

宇宙学与河外天体物理 · 物理学 2026-04-24 M. Tristram , M. Douspis , A. Gorce , S. Henrot-Versillé , L. T. Hergt , S. Ilic , L. McBride , M. Muñoz-Echeverría , E. Pointecouteau , L. Salvati