Abstract
Redshift-space clustering distortions provide one of the most powerful probes
to test the gravity theory on the largest cosmological scales. In this paper we
perform a systematic validation study of the state-of-the-art statistical
methods currently used to constrain the linear growth rate from redshift-space
distortions in the galaxy two-point correlation function. The numerical
pipelines are tested on mock halo catalogues extracted from large N-body
simulations of the standard cosmological framework, in the redshift range
$0.5złesssim2$. We consider both the monopole and quadrupole
multipole moments of the redshift-space two-point correlation function, as well
as the radial and transverse clustering wedges, in the comoving scale range
$10<r$\Mpch$<55$. Moreover, we investigate the impact of redshift measurement
errors, up to $z 0.5\%$, which introduce spurious clustering
anisotropies. We quantify the systematic uncertainties on the growth rate and
linear bias measurements due to the assumptions in the redshift-space
distortion model. Considering both the dispersion model and two widely-used
models based on perturbation theory, that is the Scoccimarro model and the TNS
model, we find that the linear growth rate is underestimated by about $5-10\%$
at $z<1$, while limiting the analysis at larger scales, $r>30$ \Mpch, the
discrepancy is reduced below $5\%$. At higher redshifts, we find instead an
overall good agreement between measurements and model predictions. The TNS
model is the one which performs better, with growth rate uncertainties below
about $3\%$. The effect of redshift errors is degenerate with the one of
small-scale random motions, and can be marginalised over in the statistical
analysis, not introducing any statistically significant bias in the linear
growth constraints, especially at $z\geq1$.
Description
Validating the methodology for constraining the linear growth rate from clustering anisotropies
Links and resources
Tags