Cosmological Simulations of X-ray Clusters: The Quest for Higher   Resolution and Essential Physics
  I review cosmological simulations of X-ray clusters. Simulations have increased in resolution dramatically and the effects of radiative cooling, star formation feedback, and chemical enrichment on the ICM are being simulated. The structure and evolution of non-radiative X-ray clusters is now well characterized. Such models fail to reproduce the observed L_x-T relation, implying the need for additional physics. Simulations adding radiative cooling produce too much cool gas and unreasonably high X-ray luminosities. Simulations including star formation and feedback appear more promising, but need further refinement. New observations should help in this regard. 
Michael L. Norman