https://www.iac.es/es/ciencia-y-tecnologia/publicaciones/fast-multipole-method-gravitational-lensing-application-high-magnification-quasar
We introduce the use of the fast multipole method (FMM) to speed up gravitational lensing ray tracing calculations. The method allows very fast calculation of...
fast multipole methodgravitational lensinghigh magnificationapplication