Description
Hybrid models use the displacement field generated by N-body simulations to precisely forecast structure formation. The distribution of galaxies is then computed employing a bias expansion technique rooted in the symmetries of galaxy formation physics. This methodology has demonstrated its ability to yield unbiased cosmological constraints across various investigations. Nonetheless, it confronts several theoretical challenges. Firstly, extending it to accommodate Redshift Space Distortions proves non-trivial due to the considerable scatter in velocities derived from N-body particles. Secondly, it lacks perturbative control, as there is no guarantee that higher-order terms in the bias expansion are suppressed relative to lower-order terms. This presentation will address these challenges and explore potential solutions.
