Acronym: pt4LCDM
Funding: Croatian Science Foundation (HRZZ), Research Projects programme
Principal investigator: Zvonimir Vlah
PI's Host institution: Ruđer Bošković Institute
Project duration: 05/12/2025 - 04/12/2028
Project Summary
The distribution of galaxies carries information about the expansion of the Universe, the growth of cosmic structure and the physics of the early Universe. Extracting this information requires accurate models of how matter clusters and how galaxies trace that matter.
The pt4LCDM project develops theoretical and computational tools for testing ΛCDM, the standard cosmological model based on cold dark matter and a cosmological constant. We use the effective field theory of large-scale structure to describe nonlinear galaxy clustering, including the effects of galaxy formation and peculiar velocities on observations.
Our work combines improved predictions for the galaxy power spectrum and bispectrum with fast numerical methods, including COBRA. We validate these tools against cosmological simulations and apply them to public galaxy-survey data from BOSS and DESI. The aim is to extract more information from these surveys and sharpen tests of cosmic expansion, gravity, neutrino masses and the initial conditions of the Universe.
Main research directions
- Accurate theoretical predictions: develop the two-loop galaxy power spectrum and one-loop galaxy bispectrum, with a consistent treatment of galaxy bias and redshift-space effects.
- Efficient computation: use and extend COBRA to make advanced theoretical calculations practical for cosmological parameter inference.
- Tests with simulations and observations: build and validate analysis pipelines, apply them to galaxy-survey data, and investigate ΛCDM and possible extensions.
Keywords: cosmology, large-scale structure, effective field theory, galaxy clustering, cosmological inference.
