The cosmology dependence of galaxy clustering and lensing from a hybrid N-body-perturbation theory model

We implement a model for the two-point statistics of biased tracers that combines dark matter dynamics from N-body simulations with an analytic Lagrangian bias expansion. Using Aemulus, a suite of N-body simulations built for emulation of cosmological observables, we emulate the cosmology dependence of these non-linear spectra from redshifts z = 0 to z = 2. We quantify the accuracy of our emulation procedure, which is sub-per cent at for the redshifts probed by upcoming surveys and improves at higher redshifts. We demonstrate its ability to describe the statistics of complex tracer samples, including those with assembly bias and baryonic effects, reliably fitting the clustering and lensing statistics of such samples at redshift z similar or equal to 0.4 to scales of k(max) approximate to 0.6 h Mpc(-1). We show that the emulator can be used for unbiased cosmological parameter inference in simulated joint clustering and galaxy-galaxy lensing analyses with data drawn from an independent N-body simulation. These results indicate that our emulator is a promising tool that can be readily applied to the analysis of current and upcoming data sets from galaxy surveys.

Automated summary

The researchers developed a model that combines dark matter dynamics with analytic bias expansion for analyzing the two-point statistics of biased tracers. They demonstrated the accuracy and applicability of their emulation procedure, showing its ability to describe complex tracer samples and fit clustering and lensing statistics effectively. The emulator is shown to be a promising tool for cosmological parameter inference and analysis of data from galaxy surveys.