  The dark matter halo profile in the inner Galaxy is very uncertain. Yet its
radial dependence toward the Galactic Center is of crucial importance for the
determination of the gamma-ray and radio fluxes originating from dark matter
annihilations. Here we use synchrotron emission to probe the dark matter energy
distribution in the inner Galaxy. We first solve the problem of the cosmic ray
diffusion on very small scales, typically smaller than 10^{-3} pc, by using a
Green's function approach and use this technique to quantify the effect of a
spiky profile (rho(r) ~ r^{-7/3}) on the morphology and intensity of the
synchrotron emission expected from dark matter. We illustrate our results using
10 and 800 GeV candidate weakly interacting dark matter particles annihilating
directly into e+ e-. Our most critical assumptions are that the dark matter is
heavier than a few GeV and directly produces a reasonable amount of electrons
and positrons in the Galaxy. We conclude that dark matter indirect detection
techniques (including the Planck experiment) could be used to shed light on the
dark matter halo profile on scales that lie beyond the capability of any
current numerical simulations.
