Speaker
Description
Understanding the interplay between dark matter physics and baryonic processes is critical for identifying the nature of dark matter. Self-interacting dark matter (SIDM), where dark matter particles can scatter with each other, is well motivated by theoretical models. Baryonic effects are often degenerate with dark matter physics, so a full picture is possible only through simulations that span a range of galaxy formation models and underlying particle physics. I will present an updated implementation of SIDM in the Gizmo code that allows for a fully customizable velocity dependence in the interaction cross section as well as anisotropy in the scattering angle. I will show results using the FIRE galaxy formation model that demonstrate the reliability of the code and the differences from existing models with constant cross sections and isotropic scattering. This code will provide a better description of the effects of SIDM in merging and infalling halos, which is essential to properly model and constrain the SIDM parameter space. In addition, it will add to the existing range of alternative dark matter models implemented in Gizmo for consistent model comparisons within the same galaxy formation model. Building upon my previous simulations using Arepo, this implementation will also allow, for the first time, comparisons of the same SIDM models between drastically different galaxy formation codes. With these models, we can identify unique signatures of classes of dark matter models and disentangle the degeneracies between dark and baryonic processes.
| Other topic / keywords: | Cosmological galaxy simulations |
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