Spectroscopic galaxy surveys have become indispensable for probing the accelerated expansion of the Universe and testing models of Dark Energy and modified gravity. Measuring the galaxies peculiar velocity offer a complementary probe for the growth rate of structure $f\sigma_8$ and the underlying matter distribution. Recent studies demonstrate that cross-correlating these observables significantly improves the precision of growth rate measurements.
In this talk, I explore the potential of combining galaxy and peculiar velocity clustering on non-linear scales to enhance cosmological constraints. Leveraging the AbacusSummit simulation suite and the halo occupation distribution framework, I present emulator models that accurately describe the non-linear clustering of galaxies and velocities in redshift space, achieving a 20% improvement in constraints on $f\sigma_8$.