Small-Scale structure
The Cold Dark Matter (CDM) paradigm has been remarkably successful at predicting large-scale properties of the Universe, from the Cosmic Microwave Background to the web of galaxies. The next frontier is to test it on galactic and sub-galactic scales. The CDM model predicts that the dark matter is cold and collisionless, however well-motivated theoretical scenarios suggest that it may be far more complex: the dark matter can consist of multiple particles that interact with themselves and regular matter through new forces. Such interesting dynamics will typically manifest on the smallest galaxy scales. Our group has been extensively studying the properties of Milky Way satellite galaxies, field dwarf galaxies, and stellar streams to better understand their sensitivity to the specifics of the dark matter model. Our work is guided by the exciting observational program underway that is opening a window to halos at unprecedentedly small mass and early epochs.