PAMELA/Fermi-LAT electron cosmic ray spectrum at $\sim$100 GeV:
  implication for dark matter annihilation signal in accordance with the 130
  GeV $\gamma$-ray line
  Recently, a tentative 130 GeV $\gamma$-ray line signal was identified by
quite a few groups. If correct it would constitute a ``smoking gun'' for dark
matter annihilations. Interestingly, the spectra of the cosmic ray electrons
detected by PAMELA and Fermi-LAT both show tiny wiggle-like structure at $\sim
100$ GeV, which might indicate a weak signal of the annihilation of $\sim 130$
GeV dark matter particles into electrons/positrons with a velocity-weighted
cross section $\langle\sigma v\rangle_{\rm \chi\chi\rightarrow e^{+}e^{-}} \sim
4\times10^{-26}~{\rm cm^{3}~s^{-1}}$. The prospect of identifying such a
potential weak dark-matter-annihilation electron and/or positron component by
AMS-02, a mission to measure the high energy cosmic ray spectra with
unprecedented accuracy, is investigated.
