Title: Discovering the Dark Sector with Astrophysical Probes
Abstract: For decades, the particle identity of dark matter has mostly been pursued via strategies whose underlying assumption is that dark matter interacts with our Standard Model at a detectable level. However, with the lack of convincing experimental evidence, the possibility that dark matter can only be probed via its gravitational interactions seems like a realistic scenario which must be addressed. Sub-galactic astrophysical structure provides probes into the microscopic nature of the dark sector and its dark matter content. For example, dark matter with sizable self interactions, dissipation, or internal degrees of freedom, can leave distinctive signatures on the properties of e.g. satellite galaxies around Milky Way-like hosts. One recent result is a new constraint on self-interacting dark matter models which pushes these theories into a parameter space with a very specific prediction: self-interactions within satellite galaxies can be either very large (so large that new dynamical effects become important), or very small (so small that such models are usually thought of as collisionless), but not intermediate. If self-interactions are large, some dwarfs of the Milky Way must be undergoing a process of gravothermal collapse, and this has distinct observational predictions which can be searched for in current and upcoming data. In this talk I will discuss a path to probe the parameter space of motivated dark sector models by understanding such effects in realistic astrophysical environments.
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