Cosmic Emulation: Fast Predictions for the Galaxy Power Spectrum

Understand

The halo occupation distribution (HOD) approach has proven to be an effective method for modeling galaxy clustering and bias.

• In this approach, galaxies of a given type are probabilistically assigned to individual halos in N-body simulations.
• In this paper, we present a fast emulator for predicting the fully nonlinear galaxy power spectrum over a range of freely specifiable HOD modeling parameters.
• The emulator is constructed using results from 100 HOD models run on a large LCDM N-body simulation, with Gaussian Process interpolation applied to a PCA-based representation of the galaxy power spectrum.