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The major contribution to the anisotropy of the temperature of the Cosmic Microwave Background (CMB) radiation is believed to come from the interaction of linear density perturbations with the radiation previous to the decoupling time.…

天体物理学 · 物理学 2015-06-24 Enrique Martinez-Gonzalez

We investigate large-angle scale temperature anisotropy in the Cosmic Microwave Background (CMB) with the Wilkinson Microwave Anisotropy Probe (WMAP) data and model the large-angle anomalies as the effect of the CMB quadrupole anisotropies…

宇宙学与河外天体物理 · 物理学 2014-11-20 Li-Ping He , Quan Guo

We investigate the effects of the presence of relic classical superhorizon inhomogeneities during inflation. This superhorizon inhomogeneity appears as a gradient locally and picks out a preferred direction. Quantum fluctuations on this…

宇宙学与河外天体物理 · 物理学 2011-07-25 Xian Gao

We simulate Planck observations by adopting a detailed model of the microwave sky including monopole, dipole, anisotropies of the cosmic microwave background (CMB) and galactic and extragalactic foregrounds. We estimate the impact of main…

天体物理学 · 物理学 2007-05-23 C. Burigana , D. Maino , N. Mandolesi , F. Villa , L. Valenziano , M. Bersanelli , L. Danese , L. Toffolatti , F. Argüeso

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

A decrement in the Cosmic Microwave Background (CMB) has been observed by the Ryle Telescope towards a pair of, possibly lensed, quasars (PC1643+4631 A&B). Assuming that the decrement is due to the Sunyaev-Zel'dovich (S-Z) effect, this is…

天体物理学 · 物理学 2007-05-23 Youri Dabrowski

The lack of power of large--angle CMB anisotropies is known to increase its statistical significance at higher Galactic latitudes, where a string--inspired pre--inflationary scale $\Delta$ can also be detected. Considering the Planck 2015…

宇宙学与河外天体物理 · 物理学 2018-03-13 A. Gruppuso , N. Kitazawa , M. Lattanzi , N. Mandolesi , P. Natoli , A. Sagnotti

Recently Finelli et al. [http://arxiv.org/abs/1405.1555] found evidence for a relatively nearby (z = 0.16) void in a galaxy catalogue in the direction of the cosmic microwave background (CMB) Cold Spot. Using a perturbative calculation,…

宇宙学与河外天体物理 · 物理学 2014-08-20 J. P. Zibin

The cosmic microwave background (CMB) anisotropy possesses the remarkable property that its power is strongly suppressed on large angular scales. This observational fact can naturally be explained by cosmological models with a non-trivial…

宇宙学与河外天体物理 · 物理学 2015-06-04 Ralf Aurich , Sven Lustig

In universes with significant curvature or cosmological constant, cosmic microwave background (CMB) anisotropies are created very recently via the Rees-Sciama or integrated Sachs-Wolfe effects. This causes the CMB anisotropies to become…

天体物理学 · 物理学 2009-10-30 S. P. Boughn , R. G. Crittenden , N. G. Turok

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

We explore the possible impact of galactic and extragalactic foregrounds on measurements of the cosmic microwave background (CMB). We find that, given our present understanding of the foregrounds, they are unlikely to qualitatively affect…

天体物理学 · 物理学 2016-08-30 Lloyd Knox

In a concordant $\Lambda$ Cold Dark Matter ($\Lambda$CDM) model, large-angle Cosmic Microwave Background (CMB) temperature anisotropy due to linear perturbations in the local universe is not negligible. We explore a possible role of an…

宇宙学与河外天体物理 · 物理学 2012-04-09 Kaiki Taro Inoue

A detailed search has been made for evidence of foreground contributions to the Cosmic Microwave Background (CMB) WMAP, such foregrounds being related to our Galaxy. We find remarkable results. On the largest angular scales we find…

天体物理学 · 物理学 2009-11-10 Tadeusz Wibig , Arnold W. Wolfendale

The advent of high resolution cosmic microwave background (CMB) experiments now allows studies on the temperature fluctuations at scales corresponding to few arcminutes and below. Though the reported excess power at $\ell \sim 2000 - 6000$…

天体物理学 · 物理学 2009-11-07 Asantha Cooray , Alessandro Melchiorri

While the major contribution to the Cosmic Microwave Background (CMB) anisotropies are the sought-after primordial fluctuations produced at the surface of last scattering, other effects produce secondary fluctuations at lower redshifts.…

天体物理学 · 物理学 2007-05-23 A. Refregier

We estimate the level of confusion to Cosmic Microwave Background anisotropy measurements caused by extragalactic infrared sources. CMB anisotropy observations at high resolution and high frequencies are especially sensitive to this…

天体物理学 · 物理学 2009-10-28 Eric Gawiser , George F. Smoot

Several anomalies have been identified which may imply a breakdown of the statistical isotropy of the cosmic microwave background (CMB). In particular, an anomalous alignment of the quadrupole and octopole and a hemispherical power…

宇宙学与河外天体物理 · 物理学 2014-11-20 Hiranya V. Peiris , Tristan L. Smith

The Cosmic Microwave Background (CMB) reaches homogeneity at relatively modest angular scales compared to the expectation of the standard $\Lambda$CDM model revealing an important challenge to the theoretical predictions. We analyze this…

Nonlinear gravitational effects of large-scale inhomogeneities on Cosmic Microwave Background (CMB) anisotropies are studied. based on the relativistic second-order theory of perturbations in nonzero-Lambda flat cosmological models, which…

天体物理学 · 物理学 2009-11-11 Kenji Tomita