The use of light polarization in weak-lensing inversions

The measurement of the integrated optical polarization of weakly gravitatio nally lensed galaxies can provide considerable constraints on lens models, The method outlined depends on the fact that the orientation of the directi on of optical polarization is not affected by weak gravitational lensing. T he angle between the semi-major axis of the imaged galaxy and the direction of integrated optical polarization thus informs one of the distortion prod uced by the gravitational lensing. Although the method depends on the polar imetric measurement of faint galaxies, large telescopes and improved techni ques should make such measurements possible in the near future.