Two-point correlation functions of X-ray selected clusters of galaxies: theoretical predictions for flux-limited surveys

We have developed a model to describe two-point correlation functions of clusters of galaxies in X-ray flux-limited surveys. Our model properly takes account of nonlinear gravitational evolution of mass fluctuations, redshift-space distortion due to linear peculiar velocity field and to finger-of-god, cluster abundance and bias evolution on the basis of the Press -- Schechter theory, the light-cone effect, and the selection function due to the X-ray flux, temperature and luminosity limits. Applying this model in representative cosmological models, we have presented quantitative predictions for X-ray selected samples feasible from the future surveys with the X-ray satellites including Astro-E, Chandra, and XMM. The comparison of these predictions and the observed cluster clustering will place important cosmological constraints which are complementary to the cluster abundance and the cosmic microwave background.