Abstract
We revisit the effect of cosmological constant on the light deflection and its role in the cosmological lens equation. First, we reexamine the motion of photon in the Schwarzschild spacetime, and explicitly describe the trajectory of photon and deflection angle up to the second order in . Then the discussion is extended to the contribution of the cosmological constant in the Schwarzschild-de Sitter or Kottler spacetime. Contrary to the previous arguments, we emphasize the following points: (a) the cosmological constant does appear in the orbital equation of light, (b) nevertheless the bending angle of light does not change its form even if since the contribution of is thoroughly absorbed into the definition of the impact parameter, and (c) the effect of is completely involved in the angular diameter distance .
- Received 31 October 2011
DOI:https://doi.org/10.1103/PhysRevD.85.023006
© 2012 American Physical Society