An Analytic Hybrid Halo + Perturbation Theory Model for Small-scale
  Correlators: Baryons, Halos, and Galaxies
  We update Halo Zeldovich Perturbation Theory (HZPT), 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 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.
