Indirect Dark Matter Signals from EGRET and PAMELA compared
  Dark Matter annihilation (DMA) may yield an excess of gamma rays and
antimatter particles, like antiprotons and positrons, above the background from
cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET
shows all the features expected from DMA. The new precise measurements of the
antiproton and positron fractions from PAMELA are compared with the EGRET
excess. It is shown that the charged particles are strongly dependent on the
propagation model used. The usual propagation models with isotropic propagation
models are incompatible with the recently observed convection in our Galaxy.
Convection leads to an order of magnitude uncertainty in the yield of charged
particles from DMA, since even a rather small convection will let drift the
charged particles in the halo to outer space. It is shown that such anisotropic
propagation models including convection prefer a contribution from DMA for the
antiprotons, but the rise in the positron fraction, as observed by PAMELA, is
incompatible with DMA, if compared with the EGRET excess. A rise in the
positron/electron ratio is expected, if the observed rise in the
proton/electron ratio is carefully fitted in a propagation model, although the
rise is slightly larger than expected, so additional local sources may
contribute as well within the limited accuracy of the data.
