Future galaxy cluster surveys: the effect of theory uncertainty on constraining cosmological parameters

Using the Fisher matrix formalism, we quantitatively investigate the constraints on a 10-dimensional space of cosmological parameters, which may be obtained with future cluster surveys. We explore the dependence of the Omega(m) constraint on both angular coverage and depth of field. We show that in each case, there is a natural cutoff beyond which the constraints on Omega(m) do not significantly improve. We also investigate the sensitivity of the constraints to changes in our knowledge of the mass-temperature (M-T) relation by including its normalization and scatter as two of the parameters in the Fisher matrix. To make our analysis more realistic, we have added, as priors, the Fisher matrices from hypothetical supernovae and cosmic microwave background experiments. We find that X-ray cluster surveys actually help to constrain the M-T relation and explore the implications of this result.