Cosmological simulations of structure formation with inelastic two-component dark matter (2cDM)

Conventional LambdaCDM paradigm assumes that dark matter is passive: it forms large-scale structure which gravitationally pulls gas into them. The rich physics of star formation, ISM physics, cosmic ray production and other baryonic effects and feedback are regulated by MHD or plasma kinetics. Such a paradigm seems to face some problems at galactic and sub-galactic scales known as the missing satellite, core-cusp, and too-big-to-fail problems. Noteworthily, one have developed a model in which dark matter may experience inelastic interactions in the dark sector. The simplest two-component dark matter model has been shown to robustly resolve the small-scale problems in N-body dark-matter-only simulations. Thus, further modeling with baryons and baryonic feedback are needed to draw accurate conclusions. Here we present simulations of cosmological volume using the full, state-of-the-art baryonic feedback model used in IllustrisTNG simulations. Our results indicate that the novel dark matter effects lead to `effective' heating of the central parts leading to the reduction of central cusps and decreased formation of dwarf satellites. We discuss some observational predictions following from our study.