中文
相关论文

相关论文: Alignment tests for low CMB multipoles

200 篇论文

Parity violation in the cosmic microwave background (CMB) radiation has been confirmed by recent Planck observation. In this paper, we extend our previous work [P. Naselsky et al. Astrophys. J. {\bf 749}, 31 (2012)] on the directional…

宇宙学与河外天体物理 · 物理学 2017-02-16 Wen Zhao

We constrain several models of the early Universe that predict a statistical anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9 maps deconvolved with beam asymmetries. As compared to previous releases of WMAP…

宇宙学与河外天体物理 · 物理学 2014-03-03 Sabir Ramazanov , Grigory Rubtsov

We investigate sets of random variables that can be arranged sequentially such that a given variable only depends conditionally on its immediate predecessor. For such sets, we show that the full joint probability distribution may be…

宇宙学与河外天体物理 · 物理学 2015-06-15 E. Gjerløw , K. Mikkelsen , H. K. Eriksen , K. M. Górski , G. Huey , J. B. Jewell , S. K. Næss , G. Rocha , D. S. Seljebotn , I. K. Wehus

The Wilkinson Microwave Anisotropy Probe WMAP has mapped the entire sky in five frequency bands between 23 and 94 GHz with polarization sensitive radiometers. We present three-year full-sky maps of the polarization and analyze them for…

In addition to its spectrum and temperature anisotropy, the 2.7K Cosmic Microwave Background is also expected to exhibit a low level of polarization. The spatial power spectrum of the polarization can provide details about the formation of…

天体物理学 · 物理学 2009-10-30 Brian Keating , Peter Timbie , Alexander Polnarev , Julia Steinberger

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,…

宇宙学与河外天体物理 · 物理学 2010-06-11 Emory F. Bunn

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…

宇宙学与河外天体物理 · 物理学 2024-02-01 C. E. Kester , A. Bernui , W. S. Hipólito-Ricaldi

The angular two-point correlation function of the temperature of the cosmic microwave background (CMB), as inferred from nearly all-sky maps, is very close to zero on large angular scales. A statistic invented to quantify this feature,…

宇宙学与河外天体物理 · 物理学 2017-05-04 Robert Knight , Lloyd Knox

A number of studies of WMAP-7 have highlighted that the power at the low multipoles in CMB power spectrum are lower than their theoretically predicted values. Angular correlation between the orientations of these low multipoles have also…

宇宙学与河外天体物理 · 物理学 2014-03-07 Santanu Das , Tarun Souradeep

We use the COBE Differential Microwave Radiometers (DMR) 4-year sky maps to model Galactic microwave emission at high latitudes (|b| > 20 deg). Cross-correlation of the DMR maps with Galactic template maps detects fluctuations in the…

天体物理学 · 物理学 2009-10-28 A. Kogut , G. Hinshaw , A. J. Banday , C. L. Bennett , K. Gorski , G. F. Smoot , E. L. Wright

Future experiments will produce high-resolution temperature maps of the cosmic microwave background (CMB) and are expected to reveal the signature of gravitational lensing by intervening large-scale structures. We construct all-sky…

天体物理学 · 物理学 2009-11-07 Christopher M. Hirata , Uros Seljak

A great deal of experimental effort is currently being devoted to the precise measurements of the cosmic microwave background (CMB) sky in temperature and polarisation. Satellites, balloon-borne, and ground-based experiments scrutinize the…

The recent release of the first light sky map of the cosmic microwave background (CMB) from the Planck satellite provides an initial opportunity for comparison with the WMAP and COBE sky maps and their reconstruction algorithms. The…

综合物理 · 物理学 2010-11-15 Keith S. Cover

According to the Cosmological Principle, the matter distribution on very large scales should have a kinematic dipole that is aligned with that of the CMB. We determine the dipole anisotropy in the number counts of two all-sky surveys of…

宇宙学与河外天体物理 · 物理学 2018-04-11 C. A. P. Bengaly , R. Maartens , M. G. Santos

The presence of matter in the path of relic photons causes distortions in the angular pattern of the cosmic microwave background (CMB) temperature fluctuations, modifying their properties in a slight but measurable way. Recently, the Planck…

宇宙学与河外天体物理 · 物理学 2017-09-11 G. A. Marques , C. P. Novaes , A. Bernui , I. S. Ferreira

We present an efficient numerical code and conduct, for the first time, a null and model-independent CMB test of statistical isotropy using Multipole Vectors (MVs) at all scales. Because MVs are insensitive to the angular power spectrum…

宇宙学与河外天体物理 · 物理学 2023-05-08 Renan A. Oliveira , Thiago S. Pereira , Miguel Quartin

We introduce and study the distribution of an estimator for the normalized bispectrum of the Cosmic Microwave Background (CMB) anisotropy. We use it to construct a goodness of fit statistic to test the coadded 53 and 90 GHz COBE-DMR 4 year…

天体物理学 · 物理学 2009-10-30 Pedro G. Ferreira , Joao Magueijo , Krzysztof M. Górski

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…

宇宙学与河外天体物理 · 物理学 2025-04-09 C. Gimeno-Amo , F. K. Hansen , E. Martínez-González , R. B. Barreiro , A. J. Banday

We revisit the possibility of using cosmological observations to constrain models that involve interactions between neutrinos and dark matter. We show that small-scale measurements of the cosmic microwave background with a few per cent…

宇宙学与河外天体物理 · 物理学 2023-10-31 Philippe Brax , Carsten van de Bruck , Eleonora Di Valentino , William Giarè , Sebastian Trojanowski

One working hypothesis on which analyses of cosmological data are based is the zero ensemble mean hypothesis, which is related to the statistical homogeneity of cosmological perturbations. This hypothesis, however, should be tested by…

宇宙学与河外天体物理 · 物理学 2014-12-24 Kiyotomo Ichiki