Galactic Dynamics and the Nature of Dark Matter
By: Matthew Walker
I will discuss efforts to use the motions of stars to learn about the nature of particles. More specifically, I will translate stellar kinematics observed in the nearest, smallest and and 'darkest' galaxies into a test of the standard hypthesis that dark matter consists of 'cold' and 'collisionless' (i.e., weakly interacting) particles. This model now seems to require that baryon-driven processes (e.g., energetic feedback from supernova explosions) alters the internal structure of galactic dark matter halos systematically with respect to predictions derived from dissipationless cosmological simulations. I will discuss future work that will let us judge whether such reconciliation is energetically feasible or whether the dark matter model requires more complexity.
