Dark Sector and Cosmological Neutrinos: The Sejong Hydrodynamical Simulation Suite

The Sejong Suite is an extensive collection of state-of-the-art high-resolution cosmological hydrodynamical simulations, developed for modeling the dark sector (massive neutrinos, dark radiation, warm dark matter). The resolution can be enhanced up to 110 billion particles in a [100 Mpc/h]³ volume - optimal for the coming generation of cosmological surveys, including the Dark Energy Spectroscopic Instrument (DESI). The suite is grouped into 3 categories, addressing different science targets. In particular, we will focus on the Systematics Suite and present a number of effects that can impact parameter constraints, related to the modeling of additional species or intrinsic to the numerical nature of our simulations. Quantifying and modeling systematics are essential tasks in order to obtain unbiased cosmological parameters and reliable likelihoods and constraints, particularly at high-redshift and at small scales, where baryons play a critical role. Finally, we will highlight the novelty of extended mixed scenarios describing the combined effects of warm dark matter, active and sterile neutrinos.