 
Summary: 198 Progress of Theoretical Physics Supplement No. 174, 2008
Spectral Functions and Transport in High Temperature QCD
Gert Aarts
Department of Physics, Swansea University, Swansea, UK
I review results on transport coefficients, spectral functions and charmonium in high
temperature QCD, obtained using nonperturbative lattice QCD simulations.
§1. Introduction
The relativistic heavy ion experiments at RHIC have made it clear that is im
portant to understand realtime and nonequilibrium processes in the quarkgluon
plasma. In this talk I focus on two developments, connected through the construc
tion of spectral functions from lattice QCD correlators: charmonium in lattice QCD
with two dynamical fermion flavours at high temperature and transport coefficients
and spectral functions at small energies obtained via the Maximum Entropy Method.
For more details and much more references I refer to a recent review.1)
§2. Charmonium
What happens to heavy quark bound states when they are immersed in a quark
gluon plasma? New answers to this old question emerged a few years ago, mainly due
to the analysis of spectral functions, constructed from euclidean lattice correlators
using the Maximum Entropy Method (MEM). Spectral function studies of charmo
nium in quenched lattice QCD indicated that S wave states (J/ and c) may survive
