Аннотации:
Peculiar-velocity surveys of the low-redshift universe have significant leverage to constrain the growth
rate of cosmic structure and test gravity. Wide-field imaging surveys combined with multiobject
spectrographs [e.g., ZTF2, Large Synoptic Survey Telescope (LSST), DESI, and 4MOST] can use type
Ia supernovae as informative tracers of the velocity field, reaching few percent constraints on the growth
rate fσ8 at z ≲ 0.2 where density tracers cannot do better than ∼10%. Combining the high-redshift DESI
survey mapping redshift space distortions with a low-redshift supernova peculiar velocity survey using
LSST and DESI can determine the gravitational growth index to σðγÞ ≈ 0.02, testing general relativity. We
study the characteristics needed for the peculiar velocity survey, and how its complementarity with
clustering surveys improves when going from a ΛCDM model assumption to a w0–wa cosmology