Full-shape analysis with simulation-based priors: cosmological parameters and the structure growth anomaly

Understand

We explore full-shape analysis with simulation-based priors, which is the simplest approach to galaxy clustering data analysis that combines effective field theory (EFT) on large scales and numerical simulations on small scales.

• The core ingredient of our approach is the prior density of EFT parameters which we extract from a suite of 10500 galaxy simulations based on the halo occupation distribution (HOD) model.
• We measure the EFT parameters with the field-level forward model, which enables us to cancel cosmic variance.
• On the theory side, we develop a new efficient approach to calculate field-level transfer functions using time-sliced perturbation theory and the logarithmic fast Fourier transform.