COSMIC COMPLEMENTARITY: H0 AND Ωm FROM COMBINING CMB EXPERIMENTS AND REDSHIFT SURVEYS

We show that upcoming CMB satellite experiments and large redshift surveys can be used together to yield 5% determinations of H0 and Ωm, an order of magnitude improvement over CMB data alone. CMB anisotropies provide the sound horizon at recombination as a standard ruler. For reasonable baryon fractions, this scale is imprinted on the galaxy power spectrum as a series of spectral features. Measuring these features in redshift space determines the Hubble constant, which in turn yields Ωm once combined with CMB data. Since the oscillations in both power spectra are frozen in at recombination, this test is insensitive to low-redshift cosmology. Subject headings: cosmology: theory – dark matter – large-scale structure of the universe – cosmic microwave background