James Sullivan, University of California, Berkeley

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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 the Zeldovich Approximation has an analytic Fourier transform and therefore is valid in both configuration space and Fourier space. The model is accurate at the 2-percent level or down to nonlinear scales, including for Luminous Red Galaxy-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 (from costly hydrodynamical simulations) and provide extended dark-matter models which are of 1 percent accuracy down to small scales. We explicitly model the non-perturbative features of halo exclusion for the halo-halo and galaxy-galaxy correlators, as well as the presence of satellite galaxies for galaxy-matter and galaxy-galaxy correlation functions. We perform density estimation using a normalizing flow applied to N-body simulations and a wide range of galaxy mocks to obtain correlations of model parameters with two cosmological parameters, mean matter density and amplitude of fluctutaions. HZPT can provide a fast, interpretable, and analytic model for combined-probe analyses of galaxy surveys using scales well into the non-linear regime.

Abstract Author(s): James M. Sullivan, UroŇ° Seljak, Sukhdeep Singh