Bounds on dark matter interpretation of Fermi-LAT GeV excess
  Annihilation of light dark matter of $m_{\rm DM} \approx (10-40)$ GeV into
the Standard Model fermions has been suggested as a possible origin of the
gamma-ray excess at GeV energies in the Fermi-LAT data. In this paper, we
examine possible model-independent signatures of such dark matter models in
other experiments such as AMS-02, colliders, and cosmic microwave background
(CMB) measurements. We point out that first generation of fermion final states
is disfavored by the existing experimental data. Currently AMS-02 positron
measurements provide stringent bounds on cross sections of dark matter
annihilation into leptonic final states, and $e^+e^-$ final state is in severe
tension with this constraint, if not ruled out. The $e^+e^-$ channel will be
complementarily verified in an early stage of ILC and future CMB measurements.
Light quark final states ($q\bar q$) are relatively strongly constrained by the
LHC and dark matter direct detection experiments even though these bounds are
model-dependent. Dark matter signals from annihilations into $q\bar{q}$
channels would be constrained by AMS-02 antiproton data which will be released
in very near future. In optimistic case, diffuse radio emission from nearby
galaxy (clusters) and the galactic center might provide another hint or limit
on dark matter annihilation.
