Deflection angle of light in an Ellis wormhole geometry
  We reexamine the light deflection by an Ellis wormhole. The bending angle as
a function of the ratio between the impact parameter and the throat radius of
the wormhole is obtained in terms of a complete elliptic integral of the first
kind. This result immediately yields asymptotic expressions in the weak field
approximation. It is shown that an expression for the deflection angle derived
(and used) in recent papers is valid at the leading order but it breaks down at
the next order because of the nontrivial spacetime topology.
