Determining gravitational lensing effects on supernovae observations
  In this paper we use a generalized version of a method originally proposed by Holz and Wald to investigate the effects from gravitational lensing on Type Ia supernovae measurements. We find that results for different mass distributions in smooth dark matter halos are very similar, making lensing effects predictable for a broad range of density profiles. Also, a sample of 100 supernovae at z = 1, should be sufficient to discriminate between the case of all dark matter in smooth halos and the extreme case of all dark matter in point-like objects. 
Edvard Mortsell