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A large sample of known and likely gamma-ray blazars has been monitored twiceper week since late 2007 at 15 GHz with the Owens Valley Radio Observatory(OVRO) 40-meter Telescope. The sample contains about 1700 sources, includingthe initial sample of 1158 sources above declination -20 degrees from theCandidate Gamma-Ray Blazar Survey (CGRaBS) plus all the blazars associated withFermi-LAT detections as released in the Fermi AGN catalogs. Using statisticallikelihood analyses, we compare the variability amplitude for varioussub-populations within our sample. These include comparisons of gamma-ray-loudversus quiet objects, BL Lac objects versus flat-spectrum radio quasars, and astudy of the variability amplitude trend with redshift. To learn about thelocation of the gamma-ray emission region we study the significance of peaks inthe radio/gamma-ray cross-correlation using Monte Carlo simulations. Firstresults for 52 sources with data from both the high-confidence Fermi Large AreaTelescope Bright AGN Sample and the first 2 years of our monitoring program arepresented. We find that assuming a power spectral density with power law slopeof -2 at 15 GHz and -1.5 at gamma-ray energies, 7 of our objects showcross-correlations at the 3sigma level. We are now studying the physicalsignificance of these correlations by further exploring the range of power lawslopes that are consistent with the data. An extension of this to a largersample and longer light curves is underway and preliminary results arepresented. We also describe KuPol, the new digital Ku-band receiver beingconstructed for the 40-meter telescope. This new receiver will provide totalintensity and linear polarization measurements over the 12-18 GHz band, with 16MHz spectral resolution. The polarization data will provide important cluesabout the magnetic field configuration in the radio emission region.

OVRO 40m blazar monitoring program: Understanding the relationship between 15 GHz radio variability properties and gamma-ray activity in blazars