## Abstract

We present a model for the redshift-space power spectrum of galaxies and demonstrate its accuracy in describing the monopole, quadrupole, and hexadecapole of the galaxy density field down to scales of

*k*= 0.4*h*Mpc^{−1}. The model describes the clustering of galaxies in the context of a halo model and the clustering of the underlying halos in redshift space using a combination of Eulerian perturbation theory and N-body simulations. The modeling of redshift-space distortions is done using the so-called distribution function approach. The final model has 13 free parameters, and each parameter is physically motivated rather than a nuisance parameter, which allows the use of well-motivated priors. We account for the Finger-of-God effect from centrals and both isolated and non-isolated satellites rather than using a single velocity dispersion to describe the combined effect. We test and validate the accuracy of the model on several sets of high-fidelity N-body simulations, as well as realistic mock catalogs designed to simulate the BOSS DR12 CMASS data set. The suite of simulations covers a range of cosmologies and galaxy bias models, providing a rigorous test of the level of theoretical systematics present in the model. The level of bias in the recovered values of f σ8 is found to be small. When including scales to*k*= 0.4*h*Mpc^{−1}, we find 15-30% gains in the statistical precision of f σ8 relative to*k*= 0.2*h*Mpc^{−1}and a roughly 10–15% improvement for the perpendicular Alcock-Paczynski parameter α⊥. Using the BOSS DR12 CMASS mocks as a benchmark for comparison, we estimate an uncertainty on*f*σ8 that is ~10–20% larger than other similar Fourier-space RSD models in the literature that use*k*≤ 0.2*h*Mpc^{−1}, suggesting that these models likely have a too-limited parametrization.Original language | English |
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Article number | 009 |

Journal | Journal of Cosmology and Astroparticle Physics |

Volume | 10 |

DOIs | |

Publication status | Published - 10 Oct 2017 |

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