CfA Colloquium: May 22, 2003

Speaker: Tony Readhead (Caltech)

Title: Two-Year Observations of the Cosmic Microwave Background with the Cosmic Background Imager

Abstract: Observations of the Cosmic Microwave Background with the Cosmic Background Imager (CBI) over multipoles up to l~3500 show excellent agreement with the WMAP results at multipoles below l~700. The high-resolution CBI results reveal, for the first time, the seeds that gave rise to clusters of galaxies, and provide good evidence from the high-l spectrum for a flat universe dominated by dark matter and dark energy, and with a scale-invariant spectrum consistent with inflationary models. The CBI results also show an excess in power at multipoles l~2500 which has been variously attributed to Sunyaev-Zel'dovich effects in galaxy clusters or Population III supernovae.