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相关论文: Probing the Origin of the Large-angle CMB Anomalie…

200 篇论文

The physics of the origin and evolution of CMB anisotropies is described. I explain the idea and status of cosmic parameter estimation and follow it up with critical comments on its dependence on model assumptions and initial conditions.

天体物理学 · 物理学 2021-04-28 Ruth Durrer

There are evidences that the cosmic microwave background (CMB) large-angle anomalies imply a departure from statistical isotropy and hence from the standard cosmological model. We propose a LCDM model extension whose dark energy component…

天体物理学 · 物理学 2008-11-26 Davi C. Rodrigues

If the Universe is open, scales larger than the curvature scale may be probed by large-angle fluctuations in the cosmic microwave background (CMB). We consider primordial adiabatic perturbations and discuss power spectra that are power laws…

天体物理学 · 物理学 2008-11-26 Marc Kamionkowski , David N. Spergel

In the near future, observations of the cosmic microwave background (CMB) anisotropies will provide accurate determinations of many fundamental cosmological parameters. In this paper, we analyse degeneracies among cosmological parameters to…

天体物理学 · 物理学 2009-10-30 G. Efstathiou , J. R. Bond

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

天体物理学 · 物理学 2007-05-23 Tomo Takahashi

Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational…

宇宙学与河外天体物理 · 物理学 2010-10-05 Duncan Hanson , Antony Lewis , Anthony Challinor

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

Analyses of recent cosmic microwave background (CMB) observations have provided increasing indications for the existence of large scale anisotropy in the universe. Given the far reaching consequences of such an anisotropy for our…

天体物理学 · 物理学 2009-09-29 A. Bernui , B. Mota , M. J. Reboucas , R. Tavakol

If the large-angular-scale anisotropy in the cosmic microwave background radiation is caused by the long-wavelength cosmological perturbations of quantum mechanical origin, they are, most likely, gravitational waves, rather than density…

广义相对论与量子宇宙学 · 物理学 2010-11-19 L. P. Grishchuk

We perform detailed calculations of cosmic microwave background (CMB) anisotropies in a CDM-dominated open universe with primordial adiabatic density perturbations for a variety of reionization histories. We show that to a great extent, the…

天体物理学 · 物理学 2009-10-22 Marc Kamionkowski , David N. Spergel , Naoshi Sugiyama

The plane-mirror symmetry previously noticed in the Cosmic Microwave Background (CMB) temperature anisotropy maps of Wilkinson Microwave Anisotropy Probe is shown to possess certain anomalous properties. The degree of the randomness…

宇宙学与河外天体物理 · 物理学 2009-11-13 V. G. Gurzadyan , T. Ghahramanyan , A. L. Kashin , H. G. Khachatryan , A. A. Kocharyan , H. Kuloghlian , D. Vetrugno , G. Yegorian

The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations…

天体物理学 · 物理学 2011-04-15 Ruth Durrer

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

The Cosmic Microwave Background (CMB) anisotropy constrains the geometry of the Universe because the positions of the acoustic peaks of the angular power spectrum depend strongly on the curvature of underlying three-dimensional space. In…

天体物理学 · 物理学 2009-11-13 J. Dunkley , M. Bucher , P. G. Ferreira , K. Moodley , C. Skordis

Fluctuations in the cosmic microwave background (CMB) temperature are being studied with ever increasing precision. Two competing types of theories might describe the origins of these fluctuations: ``inflation'' and ``defects''. Here we…

天体物理学 · 物理学 2010-04-08 Andreas Albrecht , David Coulson , Pedro Ferreira , Joao Magueijo

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

We extend the curvaton scenario presented by Erickcek et al. (2008, 2009), to explain how the even-odd multipole asymmetry of the Cosmic Microwave Background (CMB) (also called parity asymmetry, (Kim & Naselsky 2010)) and power anisotropies…

宇宙学与河外天体物理 · 物理学 2013-08-29 Hao Liu , Anne Mette Frejsel , Pavel Naselsky

We discuss selected large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. Specfically, these include alignments of the largest modes of CMB anisotropy with one another and with the geometry and…

宇宙学与河外天体物理 · 物理学 2012-01-13 Glenn D. Starkman , Craig J. Copi , Dragan Huterer , Dominik Schwarz

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

天体物理学 · 物理学 2009-11-06 Masahiro Kawasaki , Takeo Moroi , Tomo Takahashi

We discuss how an extended foreground of the cosmic microwave background (CMB) can account for the anomalies in the low multipoles of the CMB anisotropies. The distortion needed to account for the anomalies is consistent with a cold spot…

天体物理学 · 物理学 2009-11-11 L. Raul Abramo , Laerte Sodre , Carlos Alexandre Wuensche