Constraints on Cluster Properties Using X-ray and Optical Data
  In this work we show that combining different cluster data sets is a powerful tool to constrain both, the cosmology and cluster properties. We assume a model with 9 parameters and fit them to 5 cluster data sets. From that fit, we conclude that only low density universes are compatible with the previous data and we also get some interesting conclusions on the rest of parameters. 
J.M. Diego, E. Martinez-Gonzalez, J.L. Sanz, L. Cayon, J. Silk