Evolution of Dark Matter Halos and their Radio Emissions
  Radio synchrotron emission is expected as a natural by-product of the
self-annihilation of super-symmetric dark matter particles. In this work we
discuss the general properties of the radio emission expected in a wide range
of dark matter halos, from local dwarf spheroidal galaxies to large and distant
galaxy clusters with the aim to determine the neutralino dark matter detection
prospects of the Square Kilometre Array (SKA). The analysis of the SKA
detection of dark matter(DM)-induced radio emission is presented for structures
spanning a wide range of masses and redshifts, and we also analyze the limits
that the SKA can set on the thermally averaged neutralino annihilation
cross-section in the event of non-detection. To this aim, we construct a model
of the redshift evolution of the radio emissions of dark matter halos and apply
it to generate predicted fluxes from a range of neutralino masses and
annihilation channels for the dark matter halos surrounding dwarf galaxies,
galaxies and galaxy clusters. Using the available SKA performance predictions
and its ability to determine an independent measure of the magnetic field in
cosmic structures, we explore both the detailed detection prospects and the
upper-bounds that might be placed on the neutralino annihilation cross-section
in the event of non-detection. We find that the SKA can access a neutralino
parameter space far larger than that of any preceding indirect-detection
experiment, also improving on the realistic CTA detection prospects, with the
possibility of setting cross-section upper-bounds up to four orders of
magnitude below the thermal relic density bound. Additionally, we find that
neutralino radio emissions carry redshift-independent signatures of the
dominant annihilation channel and of neutralino mass, offering therefore a
means to identify such non-thermal emissions within the observing frequency
range of the SKA.
