搜索结果: 1-15 共查到“天文学 CMB”相关记录33条 . 查询时间(0.109 秒)
Statistical anisotropy of CMB as a probe of conformal rolling scenario
Statistical anisotropy CMB probe conformal rolling scenario
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2012/2/21
Search for the statistical anisotropy in the CMB data is a powerful tool for constraining models of the early Universe. In this paper we focus on the recently proposed cosmological scenario with confo...
Future constraints on variations of the fine structure constant from combined CMB and weak lensing measurements
Future constraints variations fine structure constant combined CMB weak lensing measurements
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2012/2/21
We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euc...
Isocurvature modes and Baryon Acoustic Oscillations II: gains from combining CMB and Large Scale Structure
Baryon Acoustic Oscillations combining CMB Large Scale Structure
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2011/9/29
We consider cosmological parameters estimation in the presence of a non-zero isocurvature contribution in the primordial perturbations. A previous analysis showed that even a tiny amount of isocurvatu...
WMAP 7 year constraints on CPT violation from large angle CMB anisotropies
CMBR theory CMBR experiments
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2011/10/18
We constrain the rotation angle $\alpha$ of the linear polarization of CMB photons using the large angular scale (up to $\sim 4^\circ$) signal in WMAP 7 year data. At these scales, the CMB polarizatio...
CMB radiation in an inhomogeneous spherical space
CMB radiation in an inhomogeneous spherical space
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2011/10/20
We analyse the CMB radiation in spherical 3-spaces with non-trivial topology. The focus is put on an inhomogeneous space which possesses observer dependent CMB properties. The suppression of the CMB a...
Constraints from the CMB temperature and other common observational data-sets on variable dark energy density models
Cosmology Dark energy Thermodynamics
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2011/10/13
The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline of Jetzer et al. Thi...
Detecting relic gravitational waves in the CMB: A statistical bias
Detecting relic gravitational waves statistical bias
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2011/10/13
Analyzing the imprint of relic gravitational waves (RGWs) on the cosmic microwave background (CMB) power spectra provides a way to determine the signal of RGWs. In this Letter, we discuss a statistica...
An Estimator for statistical anisotropy from the CMB bispectrum
Estimator statistical anisotropy CMB bispectrum
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2011/10/13
Various data analyses of the Cosmic Microwave Background (CMB) provide observational hints of statistical isotropy breaking. Some of these features can be studied within the framework of primordial ve...
Characterisation of the non-Gaussianity of radio and IR point-sources at CMB frequencies
ology: Cosmic Microwave Background, large scale structures Galaxiesstatistics, Infrared: galaxies Radio continuum: galaxies Methods: statistical
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2011/10/8
The present study focuses on the characterisation of the non-Gaussianity produced by radio point-sources and, for the first time, by infrared sources in the frequency range of the CMB from 30 to 350 G...
Violation of the Rotational Invariance in the CMB Bispectrum
Violation Rotational Invariance CMB Bispectrum
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2011/9/27
We investigate a statistical anisotropy on the Cosmic Microwave Background (CMB) bispectrum which can be generated from the primordial non-Gaussianity induced by quantum fluctuations of a vector field...
Non Gaussian extrema counts for CMB maps
Gaussian extrema counts maps
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2011/9/30
In the context of the geometrical analysis of weakly non Gaussian CMB maps, the 2D differential extrema counts as functions of the excursion set threshold is derived from the full moments expansion of...
W-band prototype of platelet feed-horn array for CMB polarisation measurements
platelet feed-horn array polarisation measurements
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2011/9/28
We present the design and performance of a 2x2 prototype array of corrugated feed-horns in W-band. The module is fabricated using a so-called "platelet" technique by milling Aluminum plates. This tech...
CMB Neutrino Mass Bounds and Reionization
CMB Neutrino Mass Bounds Reionization
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2011/1/11
Current cosmic microwave background (CMB) bounds on the sum of the neutrino masses assume a sudden reionization scenario described by a single parameter that determines the onset of reionization. We i...
Future CMB Constraints on Early, Cold, or Stressed Dark Energy
Future CMB Constraints on Early Cold Stressed Dark Energy
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2011/1/11
We investigate future constraints on early dark energy (EDE) achievable by the Planck and CMBPol experiments, including cosmic microwave background (CMB) lensing. For the dark energy, we include the p...
Count response model for the CMB spots
Count response model the CMB spots
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2011/1/13
The statistics of the curvature quanta generated during a stage of inflationary expansion is used to derive a count response model for the large-scale phonons determining, in the concordance lore, the...