MICROWAVE BACKGROUND CONSTRAINTS ON COSMOLOGICAL PARAMETERS

We use a high-accuracy computational code to investigate the precision with which cosmological parameters could be reconstructed by future c osmic microwave background experiments. We focus on the two planned sa tellite missions: MAP and Planck. We identify several parameter combin ations that could be determined with a few percent accuracy with the t wo missions, as well as some degeneracies among the parameters that ca nnot be accurately resolved with the temperature data alone. These deg eneracies can be broken by other astronomical measurements. Polarizati on measurements can significantly enhance the science return of both m issions by allowing a more accurate determination of some cosmological parameters, by enabling the detection of gravity waves and by probing the ionization history of the universe. We also address the question of how Gaussian the likelihood function is around the maximum and whet her gravitational lensing changes the constraints.