The overarching objective of this SciDAC-5 project is to create consistent predictions of the dark and visible Universe across redshifts, length scales and wavebands based on state-of-the-art cosmological simulations. The simulation suite will encompass large-volume, high-resolution gravity-only simulations and hydrodynamical simulations equipped with a comprehensive set of subgrid models covering both small and large volumes. The simulations will be coupled to a powerful analysis framework and associated tools to maximize the analysis flexibility and science return.

We will investigate

  • the Universe at low redshifts (z < 3) via large-volume, high-resolution gravity-only and hydrodynamical simulations targeting galaxy clustering, weak lensing, CMB lensing and cluster observations from Rubin Observatory’s LSST and SPT-3G;
  • the Universe at small scales by melding results from gravity-only and hydrodynamical simulations across cosmologies to enable the analysis of survey data from DESI and Rubin Observatory’s LSST in the nonlinear regime;
  • the Universe in the redshift range of 2 < z < 6 via small-volume, high-resolution hydrodynamical simulations targeting Lyman-α forest observations carried out by DESI and other spectroscopic probes to constrain cosmological and reionization parameters with particular emphasis on neutrino masses and study of non-CDM models.

As an important part of our effort, advanced statistical approaches will be used to explore the interplay of variables in large parameter spaces and to construct uncertainty-quantified precision prediction tools and calibration approaches.