The combination of the Cosmic Background Imager (CBI) two-year (2000+2001) total intensity observations with the first year WMAP observations leads to significantly refined estimates of basic cosmological parameters, and provides a stringent test of the scale invariance of the primordial spectrum. The CBI polarization observations from ~300 nights of observations provide a highly significant detection of polarized emission from the microwave background on the scale of the seeds of galaxy clusters, and show that the polarization spectrum is "out of step" with the total intensity spectrum, as expected for acoustic waves. The next generation of coherent detectors - large arrays of MMIC receivers - is being developed for deployment on the CBI in late 2005 and these developments will also be discussed.

Page created on December 16, 2004.