Using the Newman and Penrose [ E. T. Newman and R. Penrose J. Math. Phys. (N.Y.) 3 566 (1962)] spin-coefficient formalism, we examine the full Bianchi identities of general relativity in the context of gravitational lensing, where the matter and space-time curvature are projected into a lens plane perpendicular to the line of sight. From one component of the Bianchi identity, we provide a rigorous, new derivation of a Poisson equation for the projected matter density where the source term involves second derivatives of the observed weak gravitational lensing shear. We also show that the other components of the Bianchi identity reveal no new results. Numerical integration of the Poisson equation in test cases shows an accurate mass map can be constructed from the combination of a ground-based, wide-field image and a Hubble Space Telescope image of the same system.
Kling T.P., Campbell B. (2008). Poisson equation for weak gravitational lensing. Physical Review D, 77(12). https://doi.org/10.1103/PhysRevD.77.123012
Virtual Commons Citation
Kling, Thomas P. and Campbell, B. (2008). Poisson equation for weak gravitational lensing. In Physics Faculty Publications. Paper 10.
Available at: http://vc.bridgew.edu/physics_fac/10