FORECASTING COSMIC PARAMETER ERRORS FROM MICROWAVE BACKGROUND ANISOTROPY EXPERIMENTS

Accurate measurements of the cosmic microwave background (CMB) anisotr opies with an angular resolution of a few arcminutes can be used to de termine fundamental cosmological parameters such as the densities of b aryons, cold and hot dark matter, and certain combinations of the cosm ological constant and the curvature of the Universe to per cent-level precision. Assuming that the true theory is a variant of inflationary cold dark matter cosmologies, we calculate the accuracy with which cos mological parameters can be determined by the next generation of CMB s atellites, MAP and Planck. We pay special attention to: (i) the accura cy of the computed derivatives of the CMB power spectrum C-l; (ii) the number and choices of parameters; and (iii) the inclusion of prior kn owledge of the values of various parameters.