BibTeX

@article{2409.10937v2,
Author        = {Julia Stadler and Fabian Schmidt and Martin Reinecke},
Title         = {Fast, Accurate and Perturbative Forward Modeling of Galaxy Clustering
  Part I: Galaxies in the Restframe},
Eprint        = {2409.10937v2},
ArchivePrefix = {arXiv},
PrimaryClass  = {astro-ph.CO},
Abstract      = {Forward models of the galaxy density field enable simulation based inference
as well as field level inference of galaxy clustering. However, these analysis
techniques require forward models that are both computationally fast and robust
to modeling uncertainties in the relation between galaxies and matter. Both
requirements can be addressed with the Effective Field Theory of Large Scale
Structure. Here, we focus on the physical and numerical convergence of the
LEFTfield model. Based on the perturbative nature of the forward model, we
derive an analytic understanding of the leading numerical errors, and we
compare our estimates to high-resolution and N-body references. This allows us
to derive a set of best-practice recommendations for the numerical accuracy
parameters, which are completely specified by the desired order of the
perturbative solution and the cut-off scale. We verify these recommendations by
an extended set of parameter recovery tests from fully nonlinear mock data and
find very consistent results. A single evaluation of the forward model takes
seconds, making cosmological analyses of galaxy clustering data based on
forward models computationally feasible.},
Year          = {2024},
Month         = {Sep},
Url           = {http://arxiv.org/abs/2409.10937v2},
File          = {2409.10937v2.pdf}
}