Investigations of the QCD phase diagram using Dyson-Schwinger equations

The Dyson-Schwinger equations as one kind of functional methods provide us with a toolbox to investigate the structure of the QCD phase diagram. By solving the carefully truncated coupled set of equations the quark and gluon propagators at finite temperature and light-quark chemical potential are obtained. Those quantities give insights about the chiral and deconfinement phase transitions and have interesting analytic properties. We present results for the phase structure of QCD with Nf=2+1 and Nf=2+1+1 flavors and discuss the location of a potential critical endpoint.