The theoretical description of correlated quantum many-body systemsis one of the major challenges in current physics. Quantum correlations occur at practically all levels of complexity: from multi-photon ionization of atoms to high temperature superconductivity in solids. In general, the amount of information stored in the wavefunction makes it inaccessible to analytical or even numerical calculations. However, many dynamical observables including the energy are completely defined by the reduced two-particle density matrix.
In his PhD project Fabian develops a method to describe the time-evolution of the two-particle density matrix without knowledge of the full wavefunction.