Journal ArticleDOI
Degree Angular Scale Interferometer First Results: A Measurement of the Cosmic Microwave Background Angular Power Spectrum
N. W. Halverson,E. M. Leitch,C. Pryke,John M Kovac,John E. Carlstrom,W. L. Holzapfel,M. Dragovan,J. K. Cartwright,Brian Mason,Stephen Padin,T. J. Pearson,A. C. S. Readhead,Martin C. Shepherd +12 more
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TLDR
The first season of observations with the Degree Angular Scale Interferometer (DASI) was conducted at the South Pole in the austral summer 1999-2000, and observations throughout the following austral winter.Abstract:
We present measurements of anisotropy in the cosmic microwave background (CMB) from the first season of observations with the Degree Angular Scale Interferometer (DASI). The instrument was deployed at the South Pole in the austral summer 1999-2000, and we made observations throughout the following austral winter. We present a measurement of the CMB angular power spectrum in the range 100 < l < 900 in nine bands with fractional uncertainties in the range 10%-20% and dominated by sample variance. In this paper, we review the formalism used in the analysis, in particular the use of constraint matrices to project out contaminants such as ground and point source signals and to test for correlations with diffuse foreground templates. We find no evidence of foregrounds other than point sources in the data, and we find a maximum likelihood temperature spectral index β = -0.1 ± 0.2 (1 σ), consistent with CMB. We detect a first peak in the power spectrum at l ~ 200, in agreement with previous experiments. In addition, we detect a peak in the power spectrum at l ~ 550 and power of similar magnitude at l ~ 800, which are consistent with the second and third harmonic peaks predicted by adiabatic inflationary cosmological models.read more
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Accelerating expansion of the universe may be caused by inhomogeneities
TL;DR: In this article, the authors point out that due to the nonlinearity of the Einstein equations, a homogeneous approximation in cosmology leads to the appearance of an additional term in the Friedmann equation, associated with the spatial inhomogeneities of the metric and can be expressed in terms of density fluctuations.
Journal ArticleDOI
Late-time acceleration with steep exponential potentials
TL;DR: In this paper, the cosmological dynamics of steeper potential than exponential were studied and a simple extension of an exponential potential allowed to capture late-time cosmic acceleration and retain the tracker behavior.
Journal ArticleDOI
Screening Mechanism and Late-time Cosmology: Role of a Chameleon-Brans-Dicke Scalar Field
TL;DR: In this paper , the authors discuss a way in which the geometric scalar in a Brans-Dicke theory can evade local astronomical tests and act as a driver of the late-time cosmic acceleration.
Journal ArticleDOI
Halo Density Profiles Consistent with Asymmetric M-B Velocity Distributions-Implications on Direct Dark Matter Searches
TL;DR: In this article, the authors obtained the WIMP velocity distribution in the vicinity starting from spherically symmetric density profiles in a self consistent way by employing the Eddington approach, by adding a reasonable angular momentum dependent term in the expression of the energy.
Proceedings ArticleDOI
Big Bang Nucleosynthesis, Implications of Recent CMB Data and Supersymmetric Dark Matter
TL;DR: In this article, the BBN predictions for the abundances of the light element isotopes are reviewed and compared with recent observational data and the viability of detecting supersymmetric dark matter is discussed.
References
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Inflationary universe: A possible solution to the horizon and flatness problems
TL;DR: In this paper, the authors proposed a model of hot big-bang cosmology where the early universe is assumed to be highly homogeneous, in spite of the fact that separated regions were causally disconnected (horizon problem).
Journal ArticleDOI
A new inflationary universe scenario: A possible solution of the horizon, flatness, homogeneity, isotropy and primordial monopole problems
TL;DR: A new inflationary universe scenario is suggested in this paper, which is free of the shortcomings of the previous one and provides a possible solution of the horizon, flatness, homogeneity and isotropy problems in cosmology.
Journal ArticleDOI
Cosmology for Grand Unified Theories with Radiatively Induced Symmetry Breaking
TL;DR: In this article, the treatment of first-order phase transitions for standard grand unified theories is shown to break down for models with radiatively induced spontaneous symmetry breaking, leading to an explanation of the cosmological homogeneity, flatness, and monopole puzzles.
A New Inflationary Universe Scenario: A Possible Solution of the Horizon, Flatness, Homogeneity, Isotropy and Primordial Monopole Problems
TL;DR: A new inflationary universe scenario is suggested in this paper, which is free of the shortcomings of the previous one and provides a possible solution of the horizon, flatness, homogeneity and isotropy problems in cosmology.
Cosmology for Grand Unified Theories With Radiatively Induced Symmetry Breaking
TL;DR: In this paper, the treatment of first-order phase transitions for standard grand unified theories is shown to break down for models with radiatively induced spontaneous symmetry breaking, leading to an explanation of the cosmological homogeneity, flatness, and monopole puzzles.
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