Speaker
Description
In simulations of galaxy formation, dark matter is typically modeled as a cold, collisionless particle that interacts solely through the force of gravity. This is an excellent approximation in many aspects of structure formation, but discrepancies remain between predictions and observations especially in the density profile shape of various sizes of dark matter halos. Such discrepancies may be resolved by allowing additional interactions to occur between dark matter particles, so-called self-interacting dark matter (SIDM). SIDM is a broad class of dark matter models that encompasses a variety of reaction types and scattering cross sections. In my talk, I will focus on a subset of models that combine elastic, exothermic, and endothermic interactions in a two-state dark matter particle. In particular, I focus on models where each of these interactions occurs with significant probability. This combination of scattering provides a mechanism for endothermic scattering to excite particles from the ground state and leads to elastic and exothermic scattering in the late universe. I will present a suite of galaxy zoom-in simulations using a few representative dark matter models that show significant density cores with effects that vary across halo mass ranges and merger histories. Thus, these models are promising avenues for resolving dark matter problems like the core-cusp and diversity of shapes.
