Lattice QCD at non-vanishing temperatures and chemical potentials

Quantum Chromo-Dynamics (QCD) describes the physics of strong interactions. These phenomena are in many cases non-perturbative. A particularly interesting sector of the strong interactions is at extreme conditions. With increasing temperatures (T) we expect a transition at some T=T _c . The dominant degrees of freedom are hadrons in the low temperature phase and colored objects in the high temperature phase. Present lattice results suggest a cross-over and a critical point at some non-vanishing T and chemical potential (μ).