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We perform a validation of estimates of the growth rate of structure, described by the parameter combination fσ8, in modified gravity cosmologies. We consider an analysis pipeline based on the redshift-space distortion modeling of the clustering wedges statistic of the galaxy correlation function and apply it to mock catalogues of Lambda cold dark matter (ΛCDM) and the normal branch of Dvali-Gabadadze-Porrati (DGP) cosmologies. We employ a halo occupation distribution approach to construct our mocks, which we ensure resemble the CMASS sample from Baryon Oscillation Spectroscopic Survey (BOSS) in terms of the total galaxy number density and large-scale amplitude of the power spectrum monopole. We show that the clustering wedges model successfully recovers the true growth rate difference between DGP and ΛCDM, even for cases with over 40% enhancement in fσ8 compared to ΛCDM. The unbiased performance of the clustering wedges model allows us to use the growth rate values estimated from the BOSS DR12 data to constrain the crossover scale rc of DGP gravity to [rcH0]-1<0.97 (2σ) or rc>3090 Mpc/h, cutting into the interesting region of parameter space with rc ~H-10 using constraints from the growth of structure alone. [ABSTRACT FROM AUTHOR]

We show that, in the presence of massive neutrinos, the Galileon gravity model provides a very good fit to the current cosmic microwave background (CMB) temperature, CMB lensing and baryonic acoustic oscillation data. This model, which we dub νGalileon, when assuming its stable attractor background solution, contains the same set of free parameters as lambda cold dark matter (ΛCDM), although it leads to different expansion dynamics and nontrivial gravitational interactions. The data provide compelling evidence (≳6σ) for nonzero neutrino masses, with σmν≳0.4 eV at the 2σ level. Upcoming precision terrestrial measurements of the absolute neutrino mass scale therefore have the potential to test this model. We show that CMB lensing measurements at multipoles l≲40 will be able to discriminate between the νGalileon and ΛCDM models. Unlike ΛCDM, the νGalileon model is consistent with local determinations of the Hubble parameter. The presence of massive neutrinos lowers the value of σ8 substantially, despite of the enhanced gravitational strength on large scales. Unlike ΛCDM, the νGalileon model predicts a negative ISW effect, which is difficult to reconcile with current observational limits. [ABSTRACT FROM AUTHOR]