In this paper the deflection angle of light by a rotating Teo wormhole
spacetime is calculated in the weak limit approximation. We mainly focus on the
weak deflection angle by revealing the gravitational lensing as a partially
global topological effect. We apply the Gauss-Bonnet theorem (GBT) to the
optical geometry osculating the Teo-Randers wormhole optical geometry to
calculate the deflection angle. Furthermore we find the same result using the
standard geodesic method. We have found that the deflection angle can be
written as a sum of two terms, namely the first term is proportional to the
throat of the wormhole and depends entirely on the geometry, while the second
term is proportional to the spin angular momentum parameter of the wormhole. A
direct observation using lensing can shed light and potentially test the nature
of rotating wormholes by comparing with the black holes systems.Comment: Accepted for publication in Physical Review
