  This article investigates an extension of General Relativity based upon a
class of lifted metrics on the cotangent bundle of space-time. The dynamics of
the theory is determined by a fixed section of the cotangent bundle,
representing the momentum of a fluid flow, and Einstein's equations for the
fluid applied to the induced space-time metric on the submanifold of the
cotangent bundle defined by the image of the section. This construction is
formally analogous to the extension of Galilean Relativity by Special
Relativity, and is shown to reduce to General Relativity as the gravitational
constant approaches zero. By examining the consequences of the model for
homogeneous cosmologies, it is demonstrated that this construction globalizes
the equivalence principle, in that, the perfect fluid model of Special
Relativity is sufficient to predict both the inflationary and the current era.
