Precision cosmology with a wide area XMM cluster survey

We explore the cosmological constraints expected from wide area XMM-type cluster surveys covering 50-200 deg2, under realistic observing conditions. We perform a Fisher matrix analysis based on cluster number counts in combination with estimates of the 2-point cluster correlation function. The effect of the survey design is implemented through an observationally well tested cluster selection function. Special attention is given to the modelling of the shot noise and sample variance, which we estimate by applying our selection function to numerically simulated surveys. We then infer the constraints on the equation of state of the dark energy considering various survey configurations. We quantitatively investigate the respective impact of the cluster mass measurements, of the correlation function and of the 1<z<2 cluster population. We show that, with some 20 Ms XMM observing time, it is possible to constrain the dark energy parameters at a level which is comparable to that expected from the next generation of cosmic probes. Such a survey has also the power to provide unique insights into the physics of high redshift clusters and AGN properties.