Many-body approaches to strongly correlated electron and mesoscopic systems

Luis Craco

Institute of Theoretical Physics, Cologne University, Zuelpicher Str.77, 50937 Cologne, Germany

I will discuss the application of many-body theories, which incorporates dynamical spin, charge and orbital fluctuations in a single picture, to real materials. I will show that perturbative treatments provide new insights for the electron spectroscopy of mesoscopic (impurities and related problems) and strongly correlated electron systems. Recent applications to transition-metal oxides, based on LDA+DMFT approach, will be discussed and compared to photoemission and inverse-photoemission measurements.