Most Matter is Dark Matter, but that’s not all that Matters

Michael Kuhlen

February 07, 2013

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Abstract: High resolution simulations of Galactic Cold Dark Matter halos reveal huge amounts of substructure, both in configuration space (subhalos) and in velocity space (tidal streams and debris flow). This substructure has important consequences for efforts aiming to detect non-gravitational signatures of dark matter in the sky and in Earth-bound underground laboratories. In this talk I will first review predictions from ultra-high resolution dark matter-only simulations, and then describe two examples of how the inclusion of baryonic physics in simulations alters these expectations. One example is the abundance of massive subhalos, where baryonic physics may help to reconcile the predictions from DM-only simulations with the relatively low number of observed bright Milky Way dwarf satellite galaxies. The other example is the surprising result that baryonic physics may lead to an offset between the point of maximum dark matter density and the dynamical center of the Galaxy, which could significantly alter theoretical expectations for the dark matter annihilation signal from the Galactic Center.