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Galactic Dynamics and the Nature of Dark Matter

I will explain how to use the motions of stars to learn about the nature of particles.  More specifically, I will translate the stellar kinematics that I observe in the nearest, smallest and `darkest’ galaxies into a test of the standard hypothesis that dark matter consists of `cold’ and `collisionless’ (i.e., weakly interacting) particles.  This model escapes falsification only if baryon-driven processes (e.g., energetic feedback from supernova explosions) can alter the internal structure of galactic dark matter halos systematically with respect to predictions derived from cosmological N-body simulations.  I will identify future work, both observational and theoretical, that I expect will tell definitively whether such reconciliation is energetically feasible or whether the dark matter model requires additional complexity.

MP 102

Matthew Walker (Harvard)

February 04, 2013
15:00 - 16:00