Minimal Inflation
  Using the universal X superfield that measures in the UV the violation of
conformal invariance we build up a model of multifield inflation. The
underlying dynamics is the one controlling the natural flow of this field in
the IR to the Goldstino superfield once SUSY is broken. We show that flat
directions satisfying the slow roll conditions exist only if R-symmetry is
broken. Naturalness of our model leads to scales of SUSY breaking of the order
of 10^{11-13} Gev, a nearly scale-invariant spectrum of the initial
perturbations and negligible gravitational waves. We obtain that the inflaton
field is lighter than the gravitino by an amount determined by the slow roll
parameter eta. The existence of slow-roll conditions is directly linked to the
values of supersymmetry and R-symmetry breaking scales. We make cosmological
predictions of our model and compare them to current data.
