  A possible equivalence of scalar dark matter, the inflaton, and modified
gravity is analyzed. After a conformal mapping, the dependence of the effective
Lagrangian on the curvature is not only singular but also bifurcates into
several almost Einsteinian spaces, distinguished only by a different effective
gravitational strength and cosmological constant. A swallow tail catastrophe in
the bifurcation set indicates the possibility for the coexistence of different
Einsteinian domains in our Universe. This `triple unification' may shed new
light on the nature and large scale distribution not only of dark matter but
also on `dark energy', regarded as an effective cosmological constant, and
inflation.
