  Physical consequences are derived from the following mathematical structures:
the variational principle, Wigner's classifications of the irreducible
representations of the Poincare group and the duality invariance of the
homogeneous Maxwell equations. The analysis is carried out within the validity
domain of special relativity. Hierarchical relations between physical theories
are used. Some new results are pointed out together with their comparison with
experimental data. It is also predicted that a genuine Higgs particle will not
be detected.
