Indirect detection of Kaluza-Klein dark matter

We investigate prospects for indirect detection of Kaluza-Klein dark matter, focusing on the annihilation radiation of the first Kaluza-Klein excitation of the hypercharge gauge boson $B^{\mathrm{}\left(1\right)\mathrm{}}$ in the galactic halo; in particular we estimate neutrino, gamma-ray and synchrotron fluxes. Comparing the predicted fluxes with observational data we are able to constrain the $B^{\mathrm{}\left(1\right)\mathrm{}}$ mass (and therefore the compactification scale). The constraints depend on the specific model adopted for the dark matter density profile. For a Navarro, Frenk, and White profile the analysis of synchrotron radiation puts a lower bound on the $B^{\mathrm{}\left(1\right)\mathrm{}}$ mass of the order of $\simeq 300\mathrm{GeV}.$