Geometry of Dark Energy
  The acceleration of the universe is described as a dynamical effect of the
extrinsic curvature of space-time. By extending previous results, the extrinsic
curvature is regarded as an independent spin-2 field, determined by a set of
non-linear equations similar to Einstein's equations. In this framework, we
investigate some cosmological consequences of this class of scenarios and test
its observational viability by performing a statistical analysis with current
type Ia Supernova data.
