http://arxiv.org/abs/2301.03648
Context: Analyzing the large-scale structure (LSS) with galaxy surveys demands accurate structure formation models. Such models should ideally be fast and have a clear theoretical framework to rapidly scan a variety of cosmological parameter spaces without requiring large training data sets.
Aims: This study aims to extend Lagrangian perturbation theory (LPT), including viscosity and vorticity, to reproduce the cosmic evolution from dark matter N-body calculations at the field level.
Methods: We extend Augmented LPT (ALPT) to an Eulerian framework, dubbed eALPT. This enables modelling the stress tensor, with this introducing vorticity. To compensate that ALPT assumes curl-free fields, a fraction of the vorticity, emerging after each Eulerian transformation, is added to the subsequent timestep. The model has three free parameters apart from the choice of cosmology, redshift snapshots, cosmic volume, and the number of particles-cells.
Results: We find that the cross-correlation of the dark matter distribution as compared to N-body solvers increases at k = 1 h Mpc$^{-1}$ from ~55% with the Zel’dovich approximation (~70% with ALPT); to ~96 and 97% with eALPT, and power spectra within percentage accuracy up to k~ 0.3 and 0.7 h Mpc$^{-1}$, using three and five steps, respectively.
F. Kitaura, F. Sinigaglia, A. Balaguera-Antolínez, et. al.
Wed, 11 Jan 23
38/80
Comments: 5 pages, 2 figures