Galactic Dynamics and Local Dark Matter

Understand

The concordance Lambda Cold Dark Matter (Lambda-CDM) model for the formation of structure in the Universe, while remarkably successful at describing observations of structure on large scales, continues to be challenged by observations on galactic scales.

• Fortunately, CDM models and their various proposed alternatives make a rich variety of testable predictions that make the Local Group and our own Milky Way Galaxy key laboratories for exploring dark matter (DM) in this regime.
• However, some of the most definitive tests of local DM require microarcsecond astrometry of faint sources, an astrometric regime that is a unique niche of SIM Lite.
• This chapter explores the important and distinct contributions that can be made by SIM Lite in the exploration of galaxy dynamics and DM on galaxy scales and that have cosmological consequences.