MEASURING COSMOLOGICAL PARAMETERS WITH GALAXY SURVEYS

We assess the accuracy with which future galaxy surveys can measure co smological parameters. By breaking parameter degeneracies of the Planc k cosmic microwave background satellite, the Sloan digital sky survey may be able to reduce the Planck error bars by about an order of magni tude on the large-scale power normalization and the reionization optic al depth, down to percent levels. However, pinpointing attainable accu racies to within better than a factor of a few depends crucially on wh ether it will be possible to extract useful information from the mildl y nonlinear regime.