Dark matter self-interactions have important implications for the
distributions of dark matter in the Universe, from dwarf galaxies to galaxy
clusters. We present benchmark models that illustrate characteristic features
of dark matter that is self-interacting through a new light mediator. These
models have self-interactions large enough to change dark matter densities in
the centers of galaxies in accord with observations, while remaining compatible
with large-scale structure data and all astrophysical observations such as halo
shapes and the Bullet Cluster. These observations favor a mediator mass in the
10 - 100 MeV range and large regions of this parameter space are accessible to
direct detection experiments like LUX, SuperCDMS, and XENON1T.Comment: 4 pages, white paper for Snowmass 2013; v2: finalized version,
figures correcte
