Physics – Optics
Scientific paper
Sep 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002phdt.........8h&link_type=abstract
Thesis (PhD). CALIFORNIA INSTITUTE OF TECHNOLOGY, Source DAI-B 63/03, p. 1396, Sep 2002, 159 pages.
Physics
Optics
5
Scientific paper
The Cosmic Microwave Background (CMB) has long been recognized as an astounding source of information about the early Universe. In this thesis we describe the design, implementation, and first-year results of the Degree Angular Scale Interferometer (DASI), a compact interferometer designed to measure the angular power spectrum of the CMB. We discuss details of the optics, receivers, and power spectrum analysis, including the use of constraint matrices to project out contaminants and test for correlations with diffuse foreground templates. We present a measurement of the CMB angular power spectrum in the multipole range l ≈ 100 900 in nine bands. The measured fluctuations have a temperature spectral index of β = -0.1 ± 0.2 (1σ), consistent with CMB. We find no evidence of foregrounds other than point sources in the data. We detect a first peak in the power spectrum at l ˜ 200, a second peak in the power spectrum at l ˜ 550, and a rise in the power spectrum at l ˜ 800 which is indicative of a third, consistent with inflationary theories. Using the DASI measurement along with COBE DMR data, and adopting conservative priors on the Hubble parameter h > 0.45 and an optical depth due to reionization 0.0 ≤ τc ≤ 0.4, we constrain the total density of the Universe Ωtot = 1.04 ± 0.06, the spectral index of the primordial density fluctuations ns = 1.01+0.08-0.06 , and the physical baryon density Ωbh 2 = 0.022+0.004-0.003 , among others (all 68% confidence limits). These constraints are consistent with inflation and estimates of Ωbh 2 from Big Bang Nucleosynthesis. With prior h = 0.72 ± 0.08, we constrain the matter density Ωm = 0.40 ± 0.15, and the vacuum energy density ΩΛ = 0.60 ± 0.15, indicating from CMB data the presence of dark matter and dark energy in the Universe.
No associations
LandOfFree
A measurement of the cosmic microwave background angular power spectrum with DASI does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A measurement of the cosmic microwave background angular power spectrum with DASI, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A measurement of the cosmic microwave background angular power spectrum with DASI will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1128148