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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Journal ArticleDOI
Direct dark matter searches - Test of the Big Bounce Cosmology
TL;DR: In this article, the authors considered the possibility of using dark matter particle's mass and its interaction cross-section as a smoking gun signal of the existence of a Big Bounce at the early stage in the evolution of our currently observed universe.
Journal ArticleDOI
OVRO CMB anisotropy measurement constraints on flat-Lambda and open CDM cosmogonies
Pia Mukherjee,Tarun Souradeep,Bharat Ratra,Naoshi Sugiyama,Krzysztof M. Górski,Krzysztof M. Górski +5 more
TL;DR: In this article, the authors use Owens Valley Radio Observatory (OVRO) cosmic microwave background (CMB) anisotropy data to constrain cosmological parameters and show that the OVRO data favors an open (spatially-flat-Λ) model with Ω 0≃ 0.33 (0.1).
Posted Content
New Constraints on Dark Energy
TL;DR: New Cosmic Microwave Background, Galaxy Clustering and Supernovae type Ia data are increasingly constraining the dark energy component of our Universe While the cosmological constant scenario remains consistent with these new tight constraints, the data does not rule out the possibility that the equation of state parameter is less than -1 as mentioned in this paper.
Journal ArticleDOI
The nearly Newtonian regime in Non-Linear Theories of Gravity
TL;DR: In this article, the authors considered the Newtonian limit of models of modified gravity including higher order terms in the scalar curvature in the gravitational action and showed that models with negative powers of the curvature, like the ones used to explain the present accelerated expansion, as well as their generalization which include positive powers, can give the correct Newtonian limits, as long as the coefficients of these powers are reasonably small.
Journal ArticleDOI
The fourth gravity test and quintessence matter field
TL;DR: In this paper, the influence of the quintessence field on the time delay of null particle is found by means of an additional integral term, which reduces to the usual Schwarzschild case naturally.
References
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Journal ArticleDOI
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.
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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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