Institute for Advanced Study / Princeton University Joint Astrophysics Colloquium

Much about dark matter remains unknown and much can be learned about its nature from its distribution on sub-galactic scales. I will discuss measurements of the small-scale structure of dark matter in elliptical galaxies and in the Milky Way from gravitational lensing and stellar streams and how these measurements constrain various interesting dark matter models in a complementary manner. I will conclude by looking forward to the data-rich future ahead in the next decade, which will let us answer the fundamental question: Is dark matter cold?