"The Milky Way as a Dark Matter Laboratory" by Michael Kuhlen
February 21, 2011 - 10:00am
One of the biggest outstanding puzzles in physics today is the nature of dark matter. Although there is compelling evidence for its existence over a wide range of scales, from the Cosmic Microwave Background to dwarf galaxies, we still do not fully understand what exactly it is. Our own Milky Way galaxy and its Local Group environment presents an ideal laboratory for the study of dark matter: numerous ground and space-based experiments and observatories are gearing up to probe dark matter on Earth, in the Solar System, at the Galactic Center, in dwarf satellite galaxies, and beyond. In this talk I will describe how recent ultra-high resolution numerical simulations of the formation of the dark matter component of a galaxy like our Milky Way have provided theoretical expectations that guide these observational efforts. In particular these simulations predict a staggering abundance of gravitationally self-bound clumps of dark matter orbiting in the Milky Way's potential. I will discuss the implications of this substructure on direct and indirect detection efforts, and then show how hydrodynamical galaxy formation simulations help to explain the discrepancy between the number of observed satellite galaxies and the much greater abundance of dark matter clumps predicted by simulations.