A High Deuterium Abundance at z=0.7; Evidence for Cosmic Inhomogeneity?

Recent HST/GHRS observations of the z = 0.7010 absorber toward the QSO 1718+4807 (selected because of apparently ideal characteristics for measuring D/H) yield a D/H significantly higher D/H than some recent high-redshift measurements. Our analysis indicates D/H}= 1.8 - 2.5 x 10^{-4}. This may indicate a cosmological inhomogeneity in the deuterium abundance of at least a factor of ten.