%0 Journal Article %T A geometrical approach to gravitational lensing magnification %A Marcus C. Werner %J Physics %D 2015 %I arXiv %X The standard definition of gravitational lensing magnification is generalized to Lorentzian spacetimes, and it is shown how it can be interpreted geometrically in terms of the van Vleck determinant and the exponential map. This is joint work with Amir B. Aazami (Kavli IPMU, University of Tokyo). %U http://arxiv.org/abs/1507.05099v1