Probing the Fifth State of Matter with Relativistic Heavy Ions: A   Theoretical Overview
  I review the current status of lattice Monte-Carlo computations of the equation of state of QCD, our current understanding of the thermalization process at collider energies, and two new theoretical developments, one pertaining to the ab-initio calculation of the low-$x$ gluon structure of heavy nuclei, the other to the chaotic behavior of QCD. At the end I give a brief overview of the status of various quark-gluon plasma signatures. 
Berndt Muller