  We provide a holographic dual description of Milgrom's scaling associated
with galactic rotation curves. Our argument is based on the recent entropic
reinterpretation of Newton's laws of motion. We propose a duality between cold
dark matter and modified Newtonian dynamics (MOND). We introduce the concept of
MONDian dark matter, and discuss some of its phenomenological implications. At
cluster as well as cosmological scales, the MONDian dark matter would behave as
cold dark matter, but at the galactic scale, the MONDian dark matter would act
as MOND.
