H_0 and Odds on Cosmology

Abstract

Recent observations by the Hubble Space Telescope of Cepheids in the Virgo cluster imply a Hubble Constant $H_0=80\pm17$\ km/sec/Mpc. We attempt to clarify some issues of interpretation of these results for determining the global cosmological parameters $Ω$ and $Λ$. Using the formalism of Bayesian model comparison, the data suggest a universe with a nonzero cosmological constant $Λ>0$, but vanishing curvature: $Ω+Λ=1$.

8 Pages, uuencoded postscript. Submitted to ApJLett. Also available at file://ftp.cita.utoronto.ca/cita/andrew/papers/odds.ps