  In the external field approximation (EFA) gravity and inertia are represented
by a two-point vector that is the byproduct of symmetry breaking. The vector is
accompanied by the appearance of classical, vortical structures. Its
interaction range is, in general, that of the metric tensor, but, in the
context of a simple symmetry breaking model, the range can be made finite by
the presence of massive scalar particles. Vortices can then be produced that
conceal matter making it effectively "dark". In EFA fermion relativistic
vortices can be induced, in particular, by rotation.
