Modelling the clustering and halo occupation of Quasars with Uchuu Simulation using the Dark Energy Spectroscopic Instrument (DESI) Survey

We present results from a set of high-fidelity lightcones for the DESI One-Percent Survey (and for upcoming Year 1 data), created from the Uchuu simulation. Uchuu is an 8 Gpc³h^-3 N-body simulation that contains 2.1 trillion particles and provides high-resolution dark matter haloes and subhaloes with the Planck 2015 ΛCDM cosmology. We employ a modified Subhalo Abundance Matching (SHAM) technique (Rodriguez-Torres et al 2017) to populate the Uchuu (sub)haloes with Quasars (QSOs) in the redshift range 0.9 < z < 2.1. Our model fits the two-point clustering statistics of the One-Percent Survey reasonably well. The Uchuu QSO HOD shows agreement with an adopted Gaussian distribution for central halos with a power law for satellites. We observe a fair agreement in the large-scale bias measurements between data and mock samples and the evolution of the bias with redshift agrees with that of previous surveys. These results enhance our understanding of the galaxy-halo connection, with pivotal insights from the first DESI data for the success of the final survey.