Model-independent cosmological constraints from growth and expansion
  Reconstructing the expansion history of the Universe from type Ia supernovae
data, we fit the growth rate measurements and put model-independent constraints
on some key cosmological parameters, namely, $\Omega_\mathrm{m},\gamma$, and
$\sigma_8$. The constraints are consistent with those from the concordance
model within the framework of general relativity, but the current quality of
the data is not sufficient to rule out modified gravity models. Adding the
condition that dark energy density should be positive at all redshifts,
independently of its equation of state, further constrains the parameters and
interestingly supports the concordance model.
