Invariant Wave Equations

to the physical applications of invariant wave equations.- The general theory of invariant wave equations.- The external field problem.- Mathematics of invariant wave equations.- Method of characteristics in the external field problem or How to recognize an acausal equation when you see one.- Particles with spin S ? 1 in an external field.- Nonlinear invariant wave equations.- Structure properties of solutions of classical non-linear relativistic field equations.- Relevance of classical solutions to quantum theories.- Yang mills instantons, geometrical aspects.- Quantum theory of non-linear invariant wave (field) equations or: Super selection sectors in constructive quantum field theory.- The S-operator for spin-0 and spin-particles in time-dependent external fields.