Cosmological data analysis of f(R) gravity models
  A class of well-behaved modified gravity models with long enough matter
domination epoch and a late-time accelerated expansion is confronted with SNIa,
CMB, SDSS, BAO and H(z) galaxy ages data, as well as current measurements of
the linear growth of structure. We show that the combination of geometrical
probes and growth data exploited here allows to rule out f(R) gravity models,
in particular, the logarithmic of curvature model. We also apply solar system
tests to the models in agreement with the cosmological data. We find that the
exponential of the inverse of the curvature model satisfies all the
observational tests considered and we derive the allowed range of parameters.
Current data still allows for small deviations of Einstein gravity. Future,
high precision growth data, in combination with expansion history data, will be
able to distinguish tiny modifications of standard gravity from the LambdaCDM
model.
