Galaxy Phase-Space and Field-Level Cosmology: The Strength of Semi-Analytic Models

Published in ApJ, 2025

Natalí S. M. de Santi, Francisco Villaescusa-Navarro, Pablo Araya-Araya, et al. 2026, ApJ. doi:10.3847/1538-4357/ae84b4 https://iopscience.iop.org/article/10.3847/1538-4357/ae84b4

Paper highlights:

  • Trains a graph neural network combined with a moment neural network on semi-analytic galaxy catalogs to infer the matter density parameter Ωm.
  • Achieves ~10% precision using only galaxy positions and velocities, with strong extrapolation from L-Galaxies to other SAMs and to full hydrodynamical simulations.
  • Demonstrates robustness to astrophysical modeling, subgrid physics, and halo-profile prescriptions, highlighting the value of SAMs for cosmological inference.

You can read the paper here.