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Halpern, Mark

We have released maps and data for five years of observation of the cosmic microwave background with the Wilkinson Microwave Anisotropy Probe (WMAP) and I will review the main results in this talk. A simple 6 parameter cosmological model continues to be an excellent fit to the CMB data and to our data in conjunction with other astrophysical measurements. In particular a running spectral index is not supported by the data, and constraints that the Universe is spatially flat have increased in precision. Increased sensitivity and improvements in our understanding of the instrumental beam shape have allowed us to measure for the first time a cosmic neutrino background. Neutrinos de-coupled from other matter earlier than photons did. While they are expected to have a 2 Kelvin thermal distribution today, they comprised 10% of the energy density of the Universe at the epoch of photon de-coupling. The data also allow tighter constraints on the shape of the inflationary potential via the amplitude of a gravitational wave background new constraints on features of cosmic axions. Recorded at TRIUMF on Thursday April 17, 2008.

podcast; Science and Engineering Library; WMAP; inflation; Wilkinson microwave anisotropy probe; cosmic microwave background; ΛCDM model; lambda CDM; beam shape; baryons; Baryon Acoustic Oscillations; Gravitational radiation; cosmic neutrion background

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2017-01-11

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http://hdl.handle.net/2429/730

Unreviewed

Mark Halpern