Cluster extensions to the dynamical mean-field theory

Thomas Pruschke

Institute for Theoretical Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany

I present a unified view of cluster extensions to the so-called dynamical mean-field theory. These approaches allow to incorporate systematically non-local dynamical fluctuations which can alter the ubiquitous features of DMFT spectra quite dramatically. As a particular example I will present recent results for one-particle spectral functions of the 2D Hubbard model wich exhibit characteristic novel features as compared to standard DMFT calculations.