  The Kaluza-Klein theory and Randall-Sundrum theory are examined
comparatively, with focus on the behavior of the five dimensional (Dirac)
fermion in the dimensional reduction to four dimensions. They are properly
treated using the Cartan formalism. In the KK case, the dual property between
the electric and magnetic dipole moments is revealed in relation to the ratio
of two massive parameters: the inverse of the radius of the extra-space circle
and the 5D fermion mass. The order estimation of the couplings is done. In the
RS case, we consider the interaction with the 5D(bulk) Higgs field and the
gauge field. The chiral property, localization, anomaly phenomena are examined.
We evaluate the bulk quantum effect using the method of the induced effective
action. The electric dipole moment term naturally appears. This is a new origin
of the CP-violation. In the 4D limit, the dual relation between KK model and RS
model appears.
