QCD at non-zero temperature and density from the lattice
  The study of systems as diverse as the cores of neutron stars and heavy-ion collision experiments requires the understanding of the phase structure of QCD at non-zero temperature, T, and chemical potential, mu_q. We review some of the difficulties of performing lattice simulations of QCD with non-zero mu_q, and outline the re-weighting method used to overcome this problem. This method is used to determine the critical endpoint of QCD in the (mu_q,T) plane. We study the pressure and quark number susceptibility at small mu_q. 
C.R. Allton, S. Ejiri, S.J. Hands, O. Kaczmarek, F. Karsch, E.   Laermann and Ch. Schmidt