IMPLICATIONS FOR THE HUBBLE CONSTANT FROM THE FIRST 7 SUPERNOVAE AT Z-GREATER-THAN-OR-EQUAL-TO-0.35

The Supernova Cosmology Project has discovered over 28 supernovae (SNs ) at 0.35 < z < 0.65 in an ongoing program that uses Type Ia SNs (SN I a's) as high-redshift distance indicators. Here we present measurement s of the ratio between the locally observed and global Hubble constant s H-0(L)/H-0(G), based on the first seven SNs of this high-redshift da ta set compared with 18 SNs at z less than or equal to 0.1 from the Ca la/Tololo survey. If Omega(M) less than or equal to 1, then light-curv e width corrected SN magnitudes yield H-0(L)/H-0(G) < 1.10 (95% confid ence level) in both a Lambda = 0 and a flat universe. The analysis usi ng the SN Ia's as standard candles without a light-curve width correct ion yields similar results. These results rule out the hypothesis that the discrepant ages of the Universe derived from globular clusters an d recent measurements of the Hubble constant are attributable to a loc ally underdense bubble. Using the Cepheid-distance-calibrated absolute magnitudes for SN Ia's of Sandage et al., we can also measure the glo bal Hubble constant, H-0(G). If Omega(M) greater than or equal to 0.2, we find that H-0(G) < 70 km s(-1) Mpc(-1) in a Lambda = 0 universe an d H-0(G) < 78 km s(-1) Mpc(-1) in a flat universe, correcting the dist ant and local SN apparent magnitudes for light-curve width. Lower resu lts for H-0(G) are obtained if the magnitudes are not width-corrected.