Cosmic ray electron anisotropies as a tool to discriminate between
  exotic and astrophysical sources
  Recent results from the PAMELA, ATIC, PPB BETS and Fermi collaborations
extend the energy range in the electron flux measurement up to unexplored
energies in the hundred GeVs range confirming the bump starting at about 10GeV
already suggested by HEAT and AMS01 data . This bump can be explained by
annihilating dark matter in the context of exotic physics, or by nearby
astrophysical sources e.g. pulsars. In order to discriminate between competing
models for primary positron production, the study of anisotropies
,complementary to the spectrum determination, shows up as new tool to look for
the origin of the lepton excess. In this letter we calculate the contribution
to the electron flux given by the collection of all known gamma ray pulsars (as
listed in the ATNF catalogue) and by annihilating dark matter both in case of a
clumpy halo or in case the excess can be atributed to a nearby sizeable dark
matter clump. We address the problem of the electron anisotropy in both
scenarios and estimate the prospect that a small dipole anisotropy can be found
by the Fermi observatory.
