Dwarf Spheroidal Galaxies as a Probes of Cosmology and Dark Matter

James Bullock

The number of known dwarf satellite galaxies of the Milky Way and M31 has more than doubled in the past 5 years. Their proximity, high phase-space densities, and high mass-to-light ratios make them ideal candidates for constraining the nature of dark matter. I will discuss detailed mass models for all of the known dwarf satellites and implications for the Missing Satellites problem in LCDM. I will also discuss how dSph stellar velocities may be used to constrain the particle nature of dark matter.