A high-fidelity sky mock of DESI galaxies in the LCDM cosmology

By using N-body simulations in which different cosmologies have been assumed and by comparing them with large-scale galaxy surveys, we can constrain cosmological parameters, even ruling out some cosmological models. In this talk I will describe how we use the Uchuu simulation for this purpose.

Uchuu is an N-body dark matter simulation that has been created by an international team of researchers from Japan, Spain, USA, Argentina, Australia, Chile, France, and Italy. Uchuu has been possible thanks to being able to use ATERUI II, a supercomputer located at NAOJ which is the world’s most powerful supercomputer dedicated to astronomy. Uchuu (meaning "outer space" in Japanese) consists of 2.1 trillion particles in a computational cube with a side of 2 Gpc/h, adopting the Planck LCDM cosmology.

I will discuss how we go from the Uchuu dark matter halo catalogues to a mock galaxy light-cone. In particular, I will explain the application to BOSS and DESI Luminous Red Galaxies and the first results that we have obtained.