Cosmic Complementarity: Probing the Acceleration of the Universe

We assess the accuracy with which Ωm and ΩΛ can be measured by combining various types of upcoming experiments. Useful expressions for the Fisher information matrix are derived for classical cosmological tests involving luminosity (e.g., SN Ia), angular size, age and number counts. These geometric probes are found to be quite complementary both to each other and to inferences from cluster abundance and the cosmic microwave background (CMB). For instance, a joint analysis of SN Ia and CMB reduces the error bars on ΩΛ by about an order of magnitude compared to a separate analysis of either data set. Subject headings: galaxies: statistics — supernovae: general — large-scale structure of universe — CMB