My scientific interests are especially the study of complex charged soft matter by means of computer simulations, and the development of simple theoretical models to describe them. More precisely I am currently working on the solution properties and association behavior of flexible and semi-flexible polyelectrolytes in various solvents and under various salt concentrations and salt types. In addition I am interested in the effective pair interactions of charged colloidal particles and their phase behavior. This includes simple DNA models, and DNA protein interactions, as well as developing coarse grained models for DNA-Histone complexes. I also began investigations of ferrofluids, where special attention is given to the structure of the solution and the magnetic response functions. Another interest is the applicability of mean-field models for the description of models with long range interactions, and possible improvements beyond the mean-field approach. This include local density functional methods based on the Poisson-Boltzmann functional, as well as strong coupling theories such as Wigner-crystal methods. In addition I am interested in the development of fast methods for the computation of long range interactions. These include pure Coulomb as well as dipolar interactions in various geometries (3D-1D), and under various boundary conditions.