The QCD Phase Diagram with Effective Theories
  We study two effective theories for QCD at non-zero temperature and finite chemical potential, using local Polyakov loops as the degrees of freedom. The sign problem is solved by exactly mapping the partition function to a sum over flux and monomer variables with only real and positive weights, making the two models accessible to Monte Carlo simulation techniques. We use generalized worm algorithms and a local Metropolis update to perform the simulations and determine the phase diagram as a function of the temperature and the chemical potential. 
Ydalia Delgado, Hans Gerd Evertz, Christof Gattringer, Daniel G\"oschl
hep-lat