Electronic correlation causes a wide range of interesting phenomena, such as superconductivity or the fractional quantum hall effect. It strongly impacts our surroundings – think about defect creation through a self-trapped exciton, or, in the animal world, the adhesion of a gecko on a surface (through the van der Waals attraction). Although the underlying Coulomb interaction is « simple » and well understood, a unifying framework is still missing that would allow us to describe, analyze, understand and predict all those phenomena on the same footing. The aim of this line of research is to seek for completely new methods for the calculation of properties of correlated electron systems including ground state total energies, excitation spectra and non-equilibrium dynamics. On the other hand, better approximations are searched for well established theories (like GW), in order to go beyond today state-of-the-art.