The subject of interest here is the dynamical regime of such high energies that the velocity of the involved particles becomes non-negligible as compared to the speed of light while keeping their quantum nature. Those situations may occur for particle-particle scattering or in the interaction of matter with extremely intense laser pulses (as in experiments at GSI Helmholtzzentrum für Schwerionenforschung (GSI) and the Max Planck Institute for Nuclear Physics (MPIK)) and for numerical simulations performed at MPIK. In particular, this includes the phenomena of relativistic tunnel-recollision dynamics in multiply charged ions and laser-induced spin-orbit couplings and interferences. We seek to broaden our previous research to complex systems such as molecules, small plasmas and thin crystals in the presence of extremely intense laser pulses. On the theoretical side, advantage will be taken as well of semiclassical calculations. Furthermore, laser-induced collisions in the MeV and GeV energy regime will be investigated in detail. This involves the study of nuclear and high-energy processes for laser intensities at the limit of current feasibilities and somewhat beyond. Comparable situations to intense laser-matter interactions occur in heavy ion collisions and will be of experimental interest as well. Substantial improvements of high-precision tests of special relativity are finally envisaged.
