An analytic hybrid halo plus perturbation theory model for small-scale correlators: baryons, halos, and galaxies

We update Halo Zeldovich Perturbation Theory (HZPT, [1]), an analytic model for the two-point statistics of dark matter, to describe halo and galaxy clustering, and galaxy-matter cross-correlation on nonlinear scales. The model correcting Zeldovich has an analytic Fourier transform, and therefore is valid in both configuration space and Fourier space. The model is accurate at the 2%-level or less for P-mm (k < 1 h/Mpc), P-hm (k < 1 h/Mpc), P-hh (k < 2 h/Mpc), P-gm (k < 1 h/Mpc), P-gg (k < 1 h/Mpc), xi(mm) (r >1 Mpc/h), xi(hm) (r > 2 Mpc/h), xi(hh) (r > 2 Mpc/h), xi(gm) (r > 1 Mpc/h), xi gg (r > 2 Mpc/h), for LRG-like mock galaxies. We show that the HZPT model for matter correlators can account for the effects of a wide range of baryonic feedback models and provide two extended dark matter models which are of 1% (3%) accuracy for k < 10 (8) h/Mpc. We explicitly model the non-perturbative features of halo exclusion for the halo-halo and galaxy-galaxy correlators, as well as the presence of satellites for galaxy-matter and galaxy-galaxy correlation functions. We perform density estimation using N-body simulations and a wide range of HOD galaxy mocks to obtain correlations of model parameters with the cosmological parameters Omega(m) and sigma(8). HZPT can provide a fast, interpretable, and analytic model for combined-probe analyses of redshift surveys using scales well into the non-linear regime.

Automated summary

The updated Halo Zeldovich Perturbation Theory (HZPT) model provides an analytic and accurate description of the two-point statistics of dark matter on nonlinear scales, with applications to halo and galaxy clustering as well as galaxy-matter cross-correlation.