Non Parallels Electric and Magnetic Fields in a F.R.W. Cosmology. Classical and Quantum Gravitational Implications

At first, we discuss parallels electric and magnetic fields solutions in a gravitational background. Then, considering eletromagnetic and gravitational waves symmetries we show a particular solution for stationary gravitational waves. Finally we consider gravitation as a gauge theory (effective gravitational theory), evaluate the propagators of the model, analyze the corresponding quantum excitations and verify (confirm) the tree-level unitarity at many places of the model.