Growth-rate parameter as a function of redshift. The solid black line shows the GR-ΛCDM prediction, and the gray lines present the predictions for alternative gravity theories. The points show different forecasts for future and current stage IV surveys. The orange points show the forecast for Euclid (Amendola et al. 2018), and the red circles show those for DESI (DESI Collaboration 2016). The forecasts from DESI and Euclid are derived from the analysis of the density field. The other forecasts come from the PV field: the green triangle from ZTF SNe Ia (Carreres et al. 2023), the cyan circles from the DESI PV survey (Saulder et al. 2023), and the blue crosses from LSST SNe Ia, which are the results from the Photo-typed sample in the tomographic bins.