similar spectrum of gamma rays (see, however, Ref. [@bringmann]). The gamma ray spectrum from a WIMP which annihilates to light leptons can be quite different, however. This can be particularly important in the case of Kaluza-Klein dark matter in models with one universal extra dimension, for example, in which dark matter particles annihilate significantly to $e^+ e^-$ and $\mu^+ \mu^-$ [@kkdm].

The Galactic Center has long been considered to be one of the most promising regions of the sky in which to search for gamma rays from dark matter annihilations [@gchist]. The prospects for this depend, however, on a number of factors including the nature of the WIMP, the distribution of dark matter in the region around the Galactic Center, and our understanding of the astrophysical backgrounds.

The gamma ray spectrum produced through dark matter annihilations is given by $$\Phi_{\gamma}(E_{\gamma},\psi) = \frac{1}{2}\sigv \frac{dN_{\gamma}}{dE_{\gamma}} \frac{1}{4\pi m^2_X} \int_{\rm{los}} \rho^2(r) dl(\psi) d\psi.
\label{flux1}$$ Here, $\sigv$ is the thermally averaged WIMP annihilation cross section, $m_X$ is the mass of the WIMP, $\psi$ is the angle observed relative to the direction of the Galactic Center, $\rho(r)$ is the dark matter density as a function of distance to the Galactic Center, and the integral is performed 