Fermion systems in discrete space-time and their continuum limit

The principle of the fermionic projector provides a new model of space-time together with the mathematical framework for the formulation of physical equations. After a general introduction to the mathematical setting of fermion systems in discrete space-time, we discuss the underlying physical principles. We set up a variational principle which is symmetric under permutations of the space-time points. We describe a mechanism of spontaneous breaking of this permutation symmetry which leads to relations between the space-time points, in particular to the generation of a so-called discrete causal structure. The connection to the space-time continuum is outlined, and obtained results for the effective continuum theory are given.