X-ray Radiation from the Annihilation of Dark Matter at the Galactic   Center
  The existing and upcoming multiwavelength data from the Galactic Center suggest a comparative study in order to propose or rule out possible models which would explain the observations. In this paper we consider the X-ray synchrotron and the gamma-ray emission due to Kaluza Klein Dark Matter and define a set of parameters for the shape of the Dark Matter halo which is consistent with the observations. We show that for this class of models the existing Chandra X-ray data is more restrictive than the constraints on very high energy gamma-rays coming from HESS. 
Lars Bergstrom, Malcolm Fairbairn (Stockholm U.), Lidia Pieri (INAF   Padova & INFN Padova)