  This note is an introduction to methods of construction for Hilbert space
realizations of relativistic quantum physics. The realizations satisfy a
revision to Wightman's functional analytic axioms and exhibit interaction in
physical spacetimes. The local commutativity, relativistic invariance, positive
energy and Hilbert space realization axioms are satisfied. The revision
eliminates conjecture that a real quantum field is necessarily a Hermitian
Hilbert space operator. The resulting explicit scattering cross sections
coincide with the first contributing order from Feynman series for a neutral
scalar field.
